Systems and methods for sidelink communication

ABSTRACT

Systems, methods, and instrumentalities are described herein that may be used to determine a destination for sidelink transmission based on the priority of the transmission and/or other parameters associated with the transmission. In examples, a destination may be selected if one or more logical channels associated with the destination have a bucket size parameter exceeding a certain threshold and the one or more logical channels have a highest priority. Various other techniques are also described herein that relate to the configuration and/or report of QoS information, selection of sidelink resources, use of a minimum communication range, etc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication No. 62/824,071, filed Mar. 26, 2019, U.S. provisional patentapplication No. 62/840,805, filed Apr. 30, 2019, U.S. provisional patentapplication No. 62/867,597, filed Jun. 27, 2019, U.S. provisional patentapplication No. 62/886,161, filed Aug. 13, 2019, and U.S. provisionalpatent application No. 62/930,943, filed Nov. 5, 2019, the contents ofwhich are hereby incorporated by reference herein.

BACKGROUND

Modes of communication by wireless transmit receive units (WTRUs) mayinclude vehicular communication such as vehicle-to-everything (V2X)communication. With vehicular communication, WTRUs may communicatedirectly with each other. Use cases for V2X operations may includein-coverage scenarios (e.g., in which a WTRU may receive assistance fromthe network to transmit and/or receive V2X messages), out of coveragescenarios (e.g., in which a WTRU may use pre-configured parameters totransmit and/or receive V2X messages), and/or the like. Types of V2Xcommunication may include vehicle to vehicle or V2V communication (e.g.,vehicular WTRUs communicating with each other directly), vehicle toinfrastructure or V21 communication (e.g., a vehicular WTRUcommunicating with a roadside unit (RSU) or with a base station (eNB orgNB)), vehicle to network or V2N communication (e.g., a vehicular WTRUcommunicating with a core network), vehicle to pedestrian or V2Pcommunication (e.g., a vehicular WTRU communicating with a WTRU underspecial conditions such as low battery capacity conditions), etc.

SUMMARY

Systems, methods, and instrumentalities are described herein that mayrelate to the selection of a destination (e.g., a destination ID ordestination address associated with a destination device) for sidelinktransmission. Such transmission may utilize sidelink resources that areconfigured by a network or selected (e.g., autonomously) by a wirelesstransmit receive unit (WTRU), e.g., from a preconfigured resource pool.The WTRU may select the destination based on one or more transmissionparameters associated with the destination and/or a priority associatedwith the destination. In examples, the WTRU may identify one or morelogical channels in response to determining that the one or more logicalchannels have data available for transmission and that respective bucketsize parameters of the logical channels have a value greater than zero.On a condition of identifying the logical channels, the WTRU may selecta first destination for the sidelink transmission on a condition thatthe first destination is associated with a first logical channel thathas a highest priority (e.g., highest logical channel priority) amongthe one or more identified logical channels. The WTRU may then transmitdata associated with the first logical channel to the first destinationusing at least a portion of the resources available to the WTRU.

The WTRU may identify a second logical channel (e.g., in addition to thefirst logical channel) from the one or more identified logical channels.The WTRU may multiplex the transmission of the second logical channelwith the transmission of the first logical channel. The WTRU may selectthe second logical channel based on the second logical channel having aminimum communication range that is within a distance of the minimumcommunication range of the first logical channel and based on the secondlogical channel having a priority and a bucket size parameter exceedingcertain thresholds.

The WTRU may determine that there is a second destination associatedwith a logical channel having the same highest priority and a bucketsize parameter greater than zero. The WTRU may select the firstdestination over the second destination if the WTRU determines thatselecting the first destination may result in fewer resources beingutilized to transmit data that exceeds a bucket size requirement thanselecting the second destination (e.g., selecting the first destinationmay result in fewer resources being used to transmit non-prioritizeddata than if the second destination were selected).

The systems, methods, and instrumentalities described herein may relateto the management of quality of service (QoS) requirements. A WTRU mayuse different messages to report QoS information for different datatypes. The WTRU may report buffer status for different data types,wherein different buffer status reports (BSRs) may have differentlogical channel-to-logical channel group mappings (LCH-to-LCG mappings).The WTRU may use different messages to report different QoS information.The WTRU may utilize a multiple-stage configuration associated with QoSparameters and/or LCGs (e.g., a multi-stage BSR). The WTRU may beconfigured with multiple destination indices for a destination, e.g., sothat the WTRU may convey buffer status information with different QoScharacteristics.

The WTRU may select an amount of resources and/or one or more carriersbased on a given data rate. The WTRU may select one or more carriers fortransmission that may satisfy a given data rate. The WTRU may performcarrier/resource reselection based on rate-related triggers. The WTRUmay perform carrier and/or resource reselection based on metricsassociated with the resources used with a peer WTRU. The WTRU may sendindication of a performed carrier/resource reselection to a peer WTRU.

A minimum communication range may be defined for a WTRU. Logical channelprioritization (LCP) may be performed in accordance with one or more LCHrestrictions that may be based on the suitability of a transmissionassociated with a minimum communication range. The WTRU may select thedata or LCH used for transmission parameter selection. The WTRU may usea target minimum communication range, for example to determinetransmission parameters and/or to generate reports for a network.Transmission parameters (e.g., MCS) may be selected to attempt tomaximize a metric (e.g., spectral efficiency). The WTRU may determinecandidate resources based on a target transport block size.

A WTRU may determine an amount of allowable resources based on ameasurement of a data rate (e.g., an achievable data rate), which may bederived from a CQI report. The WTRU may reserve or select up to amaximum computed rate of selected or reserved resources based on datarate requirements of a sidelink radio bearer (SLRB) associated with theWTRU. The WTRU may temporarily exceed the maximum rate of selectedresources. The WTRU may be configured with different resource selectionparameters for a sidelink process when the WTRU exceeds a certain datarate. The WTRU may differentiate constant bit rate and non-guaranteedbit rate (non-GBR) SLRBs in a flow-to-SLRB mapping and/or in ratecomputation. The WTRU may restrict and/or prioritize a subset of SLRBsto use a specific SL process or SL carrier. The WTRU may compute maximumrates separately for different sidelink process types.

A WTRU may trigger resource reselection based on a failure or errorcondition associated with logical channel prioritization. The WTRU maydetermine one or more SL processes on which to perform resourcereselection based on one or more rate-related triggers. The WTRU maydetermine the reservation time (e.g., number of periods) for a periodicreservation based on one or more QoS parameters.

A WTRU may be configured with one or more rules for destination addressselection during logical channel prioritization. For example, the WTRUmay be configured with rules indicating how the WTRU should combineconditions or criteria for destination selection. The WTRU may select adestination address based on the value of a QoS parameter associatedwith a logical channel for that destination. The WTRU may select adestination address based on whether the destination is associated witha largest weighted bucket size parameter (e.g., bucket size Bj). TheWTRU may select a destination address based on whether the selection mayminimize data that exceeds a Bj (e.g., so that grant usage such as grantusage for non-prioritized bit rate data or grant usage not correspondingto Bj>0 may be minimized). The WTRU may select a destination addressbased on the selection may satisfy one or more (e.g., a majority of)configured bucket sizes. The WTRU may select a destination address basedon whether the selection may satisfy a greatest number of and/or amajority of the logical channels with pending data. The WTRU may selecta destination address such that a bucket size or a total bucket size maybe above a threshold. The WTRU may select a destination address based ona destination-specific bucket size. The WTRU may select a destinationaddress according to a restriction against selecting the samedestination address. The WTRU may select a destination address based ona timer such as a destination starvation avoidance timer.

The WTRU may determine which criteria (e.g., for destination selection)to use and/or the order in which the criteria are used based on channelconditions. The WTRU may determine which criteria to use and/or theorder in which the criteria are used based on criticality of thecondition. The WTRU may be configured to give certain destinationshigher priority or weight when applying a decision criteria.

A WTRU may restrict or prioritize transmissions associated with aminimum communication range that falls within a certain communicationrange of a first selected LCH. A transmitting WTRU may use best-efforttransmission parameters when a receiving WTRU is outside a minimumcommunication range (e.g., a minimum communication range associated witha SLRB). The receiving WTRU may send an indication of the WTRU'slocation and/or whether the WTRU is inside or outside a minimumcommunication range (e.g., a minimum communication range associated witha SLRB). The transmitting WTRU may be configured with a different oralternate set of transmission-related parameters when a receiving WTRUis outside of a minimum communication range (e.g., a minimumcommunication range associated with a SLRB). The transmitting WTRU maymodify a flow-to-bearer mapping for a flow when a receiving WTRU isoutside of a minimum communication range (e.g., a minimum communicationrange associated with a SLRB).

A WTRU may determine the condition(s) under which a particular orexceptional resource pool may be used. A receiving WTRU may send HARQfeedback along with a transmission range indication.

A WTRU may change one or more starvation avoidance parameters and/orbehaviors based on a congestion condition. In examples, starvationavoidance may refer to rules, operating parameters, behaviors, efforts,etc. applied by a network and/or a WTRU so that the WTRU may avoid ormitigate shortage of resources for sending or receiving a transmission.A WTRU may decide whether to select an amount of data based on a bucketsize parameter (e.g., Bj) in accordance with a channel busy ratio. TheWTRU may decide whether to increase a bucket size parameter value (e.g.,Bj) based on a measured congestion level. The WTRU may compute a bucketsize parameter (e.g., Bj) differently based on the measured congestionlevel. The WTRU may select an amount of data as a function of a bucketsize parameter (e.g., Bj) and the function may depend on the measuredcongestion level.

A WTRU may be configured to change a SLRB configuration (e.g., RLC mode)based on a channel busy ratio. The WTRU may be configured to favor(e.g., give higher priority to) transmissions with lower minimumcommunication range during congestion control. The WTRU may select anSLRB configuration that best represents the QoS profile of a flow. TheWTRU may implement one or more LCP range restrictions for a minimumcommunication range.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a system diagram illustrating an example communicationssystem in which one or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram illustrating an example wirelesstransmit/receive unit (WTRU) that may be used within the communicationssystem illustrated in FIG. 1A according to an embodiment;

FIG. 10 is a system diagram illustrating an example radio access network(RAN) and an example core network (CN) that may be used within thecommunications system illustrated in FIG. 1A according to an embodiment;and

FIG. 1D is a system diagram illustrating a further example RAN and afurther example CN that may be used within the communications systemillustrated in FIG. 1A according to an embodiment.

FIG. 2 is a diagram illustrating an example scenario for destinationselection.

FIG. 3 is a diagram illustrating an example of destination selection.

DETAILED DESCRIPTION

FIG. 1A is a diagram illustrating an example communications system 100in which one or more disclosed embodiments may be implemented. Thecommunications system 100 may be a multiple access system that providescontent, such as voice, data, video, messaging, broadcast, etc., tomultiple wireless users. The communications system 100 may enablemultiple wireless users to access such content through the sharing ofsystem resources, including wireless bandwidth. For example, thecommunications systems 100 may employ one or more channel accessmethods, such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tailunique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM(UW-OFDM), resource block-filtered OFDM, filter bank multicarrier(FBMC), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a RAN104/113, a CN 106/115, a public switched telephone network (PSTN) 108,the Internet 110, and other networks 112, though it will be appreciatedthat the disclosed embodiments contemplate any number of WTRUs, basestations, networks, and/or network elements. Each of the WTRUs 102 a,102 b, 102 c, 102 d may be any type of device configured to operateand/or communicate in a wireless environment. By way of example, theWTRUs 102 a, 102 b, 102 c, 102 d, any of which may be referred to as a“station” and/or a “STA”, may be configured to transmit and/or receivewireless signals and may include a user equipment (UE), a mobilestation, a fixed or mobile subscriber unit, a subscription-based unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watchor other wearable, a head-mounted display (HMD), a vehicle, a drone, amedical device and applications (e.g., remote surgery), an industrialdevice and applications (e.g., a robot and/or other wireless devicesoperating in an industrial and/or an automated processing chaincontexts), a consumer electronics device, a device operating oncommercial and/or industrial wireless networks, and the like. Any of theWTRUs 102 a, 102 b, 102 c and 102 d may be interchangeably referred toas a UE.

The communications systems 100 may also include a base station 114 aand/or a base station 114 b. Each of the base stations 114 a, 114 b maybe any type of device configured to wirelessly interface with at leastone of the WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to oneor more communication networks, such as the CN 106/115, the Internet110, and/or the other networks 112. By way of example, the base stations114 a, 114 b may be a base transceiver station (BTS), a Node-B, an eNodeB, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller,an access point (AP), a wireless router, and the like. While the basestations 114 a, 114 b are each depicted as a single element, it will beappreciated that the base stations 114 a, 114 b may include any numberof interconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 104/113, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals on one or morecarrier frequencies, which may be referred to as a cell (not shown).These frequencies may be in licensed spectrum, unlicensed spectrum, or acombination of licensed and unlicensed spectrum. A cell may providecoverage for a wireless service to a specific geographical area that maybe relatively fixed or that may change over time. The cell may furtherbe divided into cell sectors. For example, the cell associated with thebase station 114 a may be divided into three sectors. Thus, in oneembodiment, the base station 114 a may include three transceivers, i.e.,one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and mayutilize multiple transceivers for each sector of the cell. For example,beamforming may be used to transmit and/or receive signals in desiredspatial directions.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet(UV), visible light, etc.). The air interface 116 may be establishedusing any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104/113 and the WTRUs 102 a,102 b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 115/116/117 using wideband CDMA (WCDMA).WCDMA may include communication protocols such as High-Speed PacketAccess (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-SpeedDownlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet Access(HSUPA).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as Evolved UMTS TerrestrialRadio Access (E-UTRA), which may establish the air interface 116 usingLong Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/orLTE-Advanced Pro (LTE-A Pro).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as NR Radio Access, which mayestablish the air interface 116 using New Radio (NR).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement multiple radio access technologies. For example, thebase station 114 a and the WTRUs 102 a, 102 b, 102 c may implement LTEradio access and NR radio access together, for instance using dualconnectivity (DC) principles. Thus, the air interface utilized by WTRUs102 a, 102 b, 102 c may be characterized by multiple types of radioaccess technologies and/or transmissions sent to/from multiple types ofbase stations (e.g., a eNB and a gNB).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.11 (i.e.,Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, an industrialfacility, an air corridor (e.g., for use by drones), a roadway, and thelike. In one embodiment, the base station 114 b and the WTRUs 102 c, 102d may implement a radio technology such as IEEE 802.11 to establish awireless local area network (WLAN). In an embodiment, the base station114 b and the WTRUs 102 c, 102 d may implement a radio technology suchas IEEE 802.15 to establish a wireless personal area network (WPAN). Inyet another embodiment, the base station 114 b and the WTRUs 102 c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. Asshown in FIG. 1A, the base station 114 b may have a direct connection tothe Internet 110. Thus, the base station 114 b may not be required toaccess the Internet 110 via the CN 106/115.

The RAN 104/113 may be in communication with the CN 106/115, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. The data may have varying qualityof service (QoS) requirements, such as differing throughputrequirements, latency requirements, error tolerance requirements,reliability requirements, data throughput requirements, mobilityrequirements, and the like. The CN 106/115 may provide call control,billing services, mobile location-based services, pre-paid calling,Internet connectivity, video distribution, etc., and/or performhigh-level security functions, such as user authentication. Although notshown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or theCN 106/115 may be in direct or indirect communication with other RANsthat employ the same RAT as the RAN 104/113 or a different RAT. Forexample, in addition to being connected to the RAN 104/113, which may beutilizing a NR radio technology, the CN 106/115 may also be incommunication with another RAN (not shown) employing a GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

The CN 106/115 may also serve as a gateway for the WTRUs 102 a, 102 b,102 c, 102 d to access the PSTN 108, the Internet 110, and/or the othernetworks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) and/orthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired and/or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another CN connected to one or more RANs, whichmay employ the same RAT as the RAN 104/113 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities (e.g., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks). For example, the WTRU 102 c shown in FIG. 1A may be configuredto communicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram illustrating an example WTRU 102. As shownin FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120,a transmit/receive element 122, a speaker/microphone 124, a keypad 126,a display/touchpad 128, non-removable memory 130, removable memory 132,a power source 134, a global positioning system (GPS) chipset 136,and/or other peripherals 138, among others. It will be appreciated thatthe WTRU 102 may include any sub-combination of the foregoing elementswhile remaining consistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In an embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and/or receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

Although the transmit/receive element 122 is depicted in FIG. 1B as asingle element, the WTRU 102 may include any number of transmit/receiveelements 122. More specifically, the WTRU 102 may employ MIMOtechnology. Thus, in one embodiment, the WTRU 102 may include two ormore transmit/receive elements 122 (e.g., multiple antennas) fortransmitting and receiving wireless signals over the air interface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as NR and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs and/or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, a Virtual Reality and/or Augmented Reality (VR/AR) device, anactivity tracker, and the like. The peripherals 138 may include one ormore sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientationsensor, a proximity sensor, a temperature sensor, a time sensor; ageolocation sensor; an altimeter, a light sensor, a touch sensor, amagnetometer, a barometer, a gesture sensor, a biometric sensor, and/ora humidity sensor.

The WTRU 102 may include a full duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for both the UL (e.g., for transmission) anddownlink (e.g., for reception) may be concurrent and/or simultaneous.The full duplex radio may include an interference management unit toreduce and or substantially eliminate self-interference via eitherhardware (e.g., a choke) or signal processing via a processor (e.g., aseparate processor (not shown) or via processor 118). In an embodiment,the WRTU 102 may include a half-duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for either the UL (e.g., for transmission) or thedownlink (e.g., for reception)).

FIG. 10 is a system diagram illustrating the RAN 104 and the CN 106according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the CN 106.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and/or receive wireless signals from, the WTRU 102a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the UL and/or DL, and the like. As shown in FIG. 10, the eNode-Bs 160a, 160 b, 160 c may communicate with one another over an X2 interface.

The CN 106 shown in FIG. 10 may include a mobility management entity(MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN)gateway (or PGW) 166. While each of the foregoing elements are depictedas part of the CN 106, it will be appreciated that any of these elementsmay be owned and/or operated by an entity other than the CN operator.

The MME 162 may be connected to each of the eNode-Bs 162 a, 162 b, 162 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM and/or WCDMA.

The SGW 164 may be connected to each of the eNode Bs 160 a, 160 b, 160 cin the RAN 104 via the S1 interface. The SGW 164 may generally route andforward user data packets to/from the WTRUs 102 a, 102 b, 102 c. The SGW164 may perform other functions, such as anchoring user planes duringinter-eNode B handovers, triggering paging when DL data is available forthe WTRUs 102 a, 102 b, 102 c, managing and storing contexts of theWTRUs 102 a, 102 b, 102 c, and the like.

The SGW 164 may be connected to the PGW 166, which may provide the WTRUs102 a, 102 b, 102 c with access to packet-switched networks, such as theInternet 110, to facilitate communications between the WTRUs 102 a, 102b, 102 c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. Forexample, the CN 106 may provide the WTRUs 102 a, 102 b, 102 c withaccess to circuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. For example, the CN 106 may include,or may communicate with, an IP gateway (e.g., an IP multimedia subsystem(IMS) server) that serves as an interface between the CN 106 and thePSTN 108. In addition, the CN 106 may provide the WTRUs 102 a, 102 b,102 c with access to the other networks 112, which may include otherwired and/or wireless networks that are owned and/or operated by otherservice providers.

Although the WTRU is described in FIGS. 1A-1D as a wireless terminal, itis contemplated that in certain representative embodiments that such aterminal may use (e.g., temporarily or permanently) wired communicationinterfaces with the communication network.

In representative embodiments, the other network 112 may be a WLAN.

A WLAN in Infrastructure Basic Service Set (BSS) mode may have an AccessPoint (AP) for the BSS and one or more stations (STAs) associated withthe AP. The AP may have an access or an interface to a DistributionSystem (DS) or another type of wired/wireless network that carriestraffic in to and/or out of the BSS. Traffic to STAs that originatesfrom outside the BSS may arrive through the AP and may be delivered tothe STAs. Traffic originating from STAs to destinations outside the BSSmay be sent to the AP to be delivered to respective destinations.Traffic between STAs within the BSS may be sent through the AP, forexample, where the source STA may send traffic to the AP and the AP maydeliver the traffic to the destination STA. The traffic between STAswithin a BSS may be considered and/or referred to as peer-to-peertraffic. The peer-to-peer traffic may be sent between (e.g., directlybetween) the source and destination STAs with a direct link setup (DLS).In certain representative embodiments, the DLS may use an 802.11e DLS oran 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS)mode may not have an AP, and the STAs (e.g., all of the STAs) within orusing the IBSS may communicate directly with each other. The IBSS modeof communication may sometimes be referred to herein as an “ad-hoc” modeof communication.

When using the 802.11ac infrastructure mode of operation or a similarmode of operations, the AP may transmit a beacon on a fixed channel,such as a primary channel. The primary channel may be a fixed width(e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling.The primary channel may be the operating channel of the BSS and may beused by the STAs to establish a connection with the AP. In certainrepresentative embodiments, Carrier Sense Multiple Access with CollisionAvoidance (CSMA/CA) may be implemented, for example in in 802.11systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, maysense the primary channel. If the primary channel is sensed/detectedand/or determined to be busy by a particular STA, the particular STA mayback off. One STA (e.g., only one station) may transmit at any giventime in a given BSS.

High Throughput (HT) STAs may use a 40 MHz wide channel forcommunication, for example, via a combination of the primary 20 MHzchannel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHzwide channel.

Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz,and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may beformed by combining contiguous 20 MHz channels. A 160 MHz channel may beformed by combining 8 contiguous 20 MHz channels, or by combining twonon-contiguous 80 MHz channels, which may be referred to as an 80+80configuration. For the 80+80 configuration, the data, after channelencoding, may be passed through a segment parser that may divide thedata into two streams. Inverse Fast Fourier Transform (IFFT) processing,and time domain processing, may be done on each stream separately. Thestreams may be mapped on to the two 80 MHz channels, and the data may betransmitted by a transmitting STA. At the receiver of the receiving STA,the above described operation for the 80+80 configuration may bereversed, and the combined data may be sent to the Medium Access Control(MAC).

Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. Thechannel operating bandwidths, and carriers, are reduced in 802.11af and802.11ah relative to those used in 802.11n, and 802.11ac. 802.11afsupports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space(TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and16 MHz bandwidths using non-TVWS spectrum. According to a representativeembodiment, 802.11ah may support Meter Type Control/Machine-TypeCommunications, such as MTC devices in a macro coverage area. MTCdevices may have certain capabilities, for example, limited capabilitiesincluding support for (e.g., only support for) certain and/or limitedbandwidths. The MTC devices may include a battery with a battery lifeabove a threshold (e.g., to maintain a very long battery life).

WLAN systems, which may support multiple channels, and channelbandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include achannel which may be designated as the primary channel. The primarychannel may have a bandwidth equal to the largest common operatingbandwidth supported by all STAs in the BSS. The bandwidth of the primarychannel may be set and/or limited by a STA, from among all STAs inoperating in a BSS, which supports the smallest bandwidth operatingmode. In the example of 802.11ah, the primary channel may be 1 MHz widefor STAs (e.g., MTC type devices) that support (e.g., only support) a 1MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes.Carrier sensing and/or Network Allocation Vector (NAV) settings maydepend on the status of the primary channel. If the primary channel isbusy, for example, due to a STA (which supports only a 1 MHz operatingmode), transmitting to the AP, the entire available frequency bands maybe considered busy even though a majority of the frequency bands remainsidle and may be available.

In the United States, the available frequency bands, which may be usedby 802.11ah, are from 902 MHz to 928 MHz. In Korea, the availablefrequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the availablefrequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidthavailable for 802.11ah is 6 MHz to 26 MHz depending on the country code.

FIG. 1D is a system diagram illustrating the RAN 113 and the CN 115according to an embodiment. As noted above, the RAN 113 may employ an NRradio technology to communicate with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The RAN 113 may also be in communication with theCN 115.

The RAN 113 may include gNBs 180 a, 180 b, 180 c, though it will beappreciated that the RAN 113 may include any number of gNBs whileremaining consistent with an embodiment. The gNBs 180 a, 180 b, 180 cmay each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the gNBs 180 a, 180 b, 180 c may implement MIMO technology. For example,gNBs 180 a, 108 b may utilize beamforming to transmit signals to and/orreceive signals from the gNBs 180 a, 180 b, 180 c. Thus, the gNB 180 a,for example, may use multiple antennas to transmit wireless signals to,and/or receive wireless signals from, the WTRU 102 a. In an embodiment,the gNBs 180 a, 180 b, 180 c may implement carrier aggregationtechnology. For example, the gNB 180 a may transmit multiple componentcarriers to the WTRU 102 a (not shown). A subset of these componentcarriers may be on unlicensed spectrum while the remaining componentcarriers may be on licensed spectrum. In an embodiment, the gNBs 180 a,180 b, 180 c may implement Coordinated Multi-Point (CoMP) technology.For example, WTRU 102 a may receive coordinated transmissions from gNB180 a and gNB 180 b (and/or gNB 180 c).

The WTRUs 102 a, 102 b, 102 c may communicate with gNBs 180 a, 180 b,180 c using transmissions associated with a scalable numerology. Forexample, the OFDM symbol spacing and/or OFDM subcarrier spacing may varyfor different transmissions, different cells, and/or different portionsof the wireless transmission spectrum. The WTRUs 102 a, 102 b, 102 c maycommunicate with gNBs 180 a, 180 b, 180 c using subframe or transmissiontime intervals (TTIs) of various or scalable lengths (e.g., containingvarying number of OFDM symbols and/or lasting varying lengths ofabsolute time).

The gNBs 180 a, 180 b, 180 c may be configured to communicate with theWTRUs 102 a, 102 b, 102 c in a standalone configuration and/or anon-standalone configuration. In the standalone configuration, WTRUs 102a, 102 b, 102 c may communicate with gNBs 180 a, 180 b, 180 c withoutalso accessing other RANs (e.g., such as eNode-Bs 160 a, 160 b, 160 c).In the standalone configuration, WTRUs 102 a, 102 b, 102 c may utilizeone or more of gNBs 180 a, 180 b, 180 c as a mobility anchor point. Inthe standalone configuration, WTRUs 102 a, 102 b, 102 c may communicatewith gNBs 180 a, 180 b, 180 c using signals in an unlicensed band. In anon-standalone configuration WTRUs 102 a, 102 b, 102 c may communicatewith/connect to gNBs 180 a, 180 b, 180 c while also communicatingwith/connecting to another RAN such as eNode-Bs 160 a, 160 b, 160 c. Forexample, WTRUs 102 a, 102 b, 102 c may implement DC principles tocommunicate with one or more gNBs 180 a, 180 b, 180 c and one or moreeNode-Bs 160 a, 160 b, 160 c substantially simultaneously. In thenon-standalone configuration, eNode-Bs 160 a, 160 b, 160 c may serve asa mobility anchor for WTRUs 102 a, 102 b, 102 c and gNBs 180 a, 180 b,180 c may provide additional coverage and/or throughput for servicingWTRUs 102 a, 102 b, 102 c.

Each of the gNBs 180 a, 180 b, 180 c may be associated with a particularcell (not shown) and may be configured to handle radio resourcemanagement decisions, handover decisions, scheduling of users in the ULand/or DL, support of network slicing, dual connectivity, interworkingbetween NR and E-UTRA, routing of user plane data towards User PlaneFunction (UPF) 184 a, 184 b, routing of control plane informationtowards Access and Mobility Management Function (AMF) 182 a, 182 b andthe like. As shown in FIG. 1D, the gNBs 180 a, 180 b, 180 c maycommunicate with one another over an Xn interface.

The CN 115 shown in FIG. 1D may include at least one AMF 182 a, 182 b,at least one UPF 184 a,184 b, at least one Session Management Function(SMF) 183 a, 183 b, and possibly a Data Network (DN) 185 a, 185 b. Whileeach of the foregoing elements are depicted as part of the CN 115, itwill be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The AMF 182 a, 182 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N2 interface and may serve as acontrol node. For example, the AMF 182 a, 182 b may be responsible forauthenticating users of the WTRUs 102 a, 102 b, 102 c, support fornetwork slicing (e.g., handling of different PDU sessions with differentrequirements), selecting a particular SMF 183 a, 183 b, management ofthe registration area, termination of NAS signaling, mobilitymanagement, and the like. Network slicing may be used by the AMF 182 a,182 b in order to customize CN support for WTRUs 102 a, 102 b, 102 cbased on the types of services being utilized WTRUs 102 a, 102 b, 102 c.For example, different network slices may be established for differentuse cases such as services relying on ultra-reliable low latency (URLLC)access, services relying on enhanced massive mobile broadband (eMBB)access, services for machine type communication (MTC) access, and/or thelike. The AMF 162 may provide a control plane function for switchingbetween the RAN 113 and other RANs (not shown) that employ other radiotechnologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP accesstechnologies such as WiFi.

The SMF 183 a, 183 b may be connected to an AMF 182 a, 182 b in the CN115 via an N11 interface. The SMF 183 a, 183 b may also be connected toa UPF 184 a, 184 b in the CN 115 via an N4 interface. The SMF 183 a, 183b may select and control the UPF 184 a, 184 b and configure the routingof traffic through the UPF 184 a, 184 b. The SMF 183 a, 183 b mayperform other functions, such as managing and allocating UE IP address,managing PDU sessions, controlling policy enforcement and QoS, providingdownlink data notifications, and the like. A PDU session type may beIP-based, non-IP based, Ethernet-based, and the like.

The UPF 184 a, 184 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N3 interface, which may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between the WTRUs 102a, 102 b, 102 c and IP-enabled devices. The UPF 184, 184 b may performother functions, such as routing and forwarding packets, enforcing userplane policies, supporting multi-homed PDU sessions, handling user planeQoS, buffering downlink packets, providing mobility anchoring, and thelike.

The CN 115 may facilitate communications with other networks. Forexample, the CN 115 may include, or may communicate with, an IP gateway(e.g., an IP multimedia subsystem (IMS) server) that serves as aninterface between the CN 115 and the PSTN 108. In addition, the CN 115may provide the WTRUs 102 a, 102 b, 102 c with access to the othernetworks 112, which may include other wired and/or wireless networksthat are owned and/or operated by other service providers. In oneembodiment, the WTRUs 102 a, 102 b, 102 c may be connected to a localData Network (DN) 185 a, 185 b through the UPF 184 a, 184 b via the N3interface to the UPF 184 a, 184 b and an N6 interface between the UPF184 a, 184 b and the DN 185 a, 185 b.

In view of FIGS. 1A-1D, and the corresponding description of FIGS.1A-1D, one or more, or all, of the functions described herein withregard to one or more of: WTRU 102 a-d, Base Station 114 a-b, eNode-B160 a-c, MME 162, SGW 164, PGW 166, gNB 180 a-c, AMF 182 a-b, UPF 184a-b, SMF 183 a-b, DN 185 a-b, and/or any other device(s) describedherein, may be performed by one or more emulation devices (not shown).The emulation devices may be one or more devices configured to emulateone or more, or all, of the functions described herein. For example, theemulation devices may be used to test other devices and/or to simulatenetwork and/or WTRU functions.

The emulation devices may be designed to implement one or more tests ofother devices in a lab environment and/or in an operator networkenvironment. For example, the one or more emulation devices may performthe one or more, or all, functions while being fully or partiallyimplemented and/or deployed as part of a wired and/or wirelesscommunication network in order to test other devices within thecommunication network. The one or more emulation devices may perform theone or more, or all, functions while being temporarilyimplemented/deployed as part of a wired and/or wireless communicationnetwork. The emulation device may be directly coupled to another devicefor purposes of testing and/or may performing testing using over-the-airwireless communications.

The one or more emulation devices may perform the one or more, includingall, functions while not being implemented/deployed as part of a wiredand/or wireless communication network. For example, the emulationdevices may be utilized in a testing scenario in a testing laboratoryand/or a non-deployed (e.g., testing) wired and/or wirelesscommunication network in order to implement testing of one or morecomponents. The one or more emulation devices may be test equipment.Direct RF coupling and/or wireless communications via RF circuitry(e.g., which may include one or more antennas) may be used by theemulation devices to transmit and/or receive data.

V2X communication may be performed in various modes (e.g., in at leasttwo modes). In a first mode, the network (e.g., an eNB or gNB) mayprovide a WTRU with a scheduling assignment for V2X transmissions (e.g.,for V2X sidelink transmissions). This first mode may be referred hereinas NR Mode 1 (and/or simply mode 1), LTE Mode 3 (e.g., or simply Mode3), and/or a network scheduled transmission mode. In a second mode, aWTRU may autonomously select resources from a configured (e.g.,pre-configured) resource pool. This second mode may be referred hereinas LTE Mode 4 (e.g., or simply Mode 4), NR Mode 2 (e.g., or simply Mode2 and/or by reference to various sub-modes such as 2a, 2b, 2c, 2d,etc.), and/or an autonomous scheduling mode. Multiple categories ofresource pools may be defined including, for example, receiving poolsthat a WTRU may monitor for receiving V2X transmissions, and/ortransmitting pools from which a WTRU may select resources fortransmitting information (e.g., such as in autonomous scheduling mode,e.g., in Mode 4). For WTRUs configured to operate in certain modes(e.g., Mode 3), transmitting pools may not be configured or may not beused.

Resource pools (e.g., for V2X communication) may be signaled (e.g.,semi-statically or semi-persistently) to a WTRU, for example, via radioresource control (RRC) signaling. In certain modes (e.g., in anautonomous scheduling mode, e.g., Mode 4), a WTRU may perform sensing(e.g., measurements) before selecting a resource from a resource pool(e.g., from an RRC configured transmitting pool). Dynamic resource poolreconfiguration may or may not be supported. Resource pool configurationmay be carried in a system information block (SIB), via dedicated RRCsignaling, etc.

A New Radio (NR) system may support use cases such as enhanced MobileBroadband (eMBB) and/or ultra-high reliability and low latencycommunications (URLLC). An NR system may support enhanced V2X (eV2X)communication. eV2X communication services may include services forsafety and non-safety scenarios such as, for example, sensor sharing,automated driving, vehicle platooning, remote driving, and/or the like.Different eV2X services may have different performance requirements. Forexample, 3 ms latency may be required in some eV2X services.

One or more of the following use cases may be supported. Vehiclesplatooning may be supported to enable vehicles to dynamically form agroup travelling together. One or more (e.g., all) of the vehicles inthe platoon may receive data (e.g., periodic data) from a lead vehicle,for example, to carry on platoon operations. Such data may allow thedistance between vehicles to be shortened. For example, when measured intime terms, the gap distance between vehicles can be short (e.g., lessthan a second). This may allow vehicles that follow the lead vehicle tobe autonomously driven.

Advanced driving may be supported to enable semi-automated orfully-automated driving. Longer inter-vehicle distance may be assumed inthese use cases. A (e.g. each) vehicle and/or RSU may share dataobtained from local sensors with vehicles in its proximity, e.g., thusallowing the vehicles to coordinate their trajectories or maneuvers. A(e.g., each) vehicle may share its driving intention with vehicles inits proximity, e.g., to promote safe traveling, collision avoidance, andtraffic efficiency.

Extended sensors may be supported to enable the exchange of raw orprocessed data such as data gathered through local sensors or livevideo/audio data among vehicles, RSUs, devices of pedestrians, V2Xapplication servers, etc. As a result, vehicles may enhance theperception of their environment beyond what the vehicles' own sensorscan detect so that the vehicles may have a more holistic view of thelocal situations.

Remote driving may be supported to enable a remote driver or a V2Xapplication to operate a vehicle remotely, e.g., for people who cannotdrive themselves or to maneuver a remote vehicle located in a dangerousenvironment. In examples (e.g., where environmental variations arelimited and routes are predictable such as for public transportation),driving may utilize (e.g., be based on) cloud computing. Access tocloud-based back-end service platforms may be considered in such usecases.

A WTRU engaging in V2X services may support (e.g., simultaneouslysupport) multiple wireless communication technologies (e.g., NR and LTEsidelink communication technologies).

As discussed herein, V2X communication may be performed in anetwork-scheduled mode and/or an autonomous mode. Such an autonomousmode may include a plurality of submodes. For example, in a firstsubmode (e.g., Mode 2a), a WTRU may autonomously select sidelinkresources for transmission. In a second submode (e.g., Mode 2c), a WTRUmay be configured with a network configured grant (e.g., similar to atype-1 grant) for sidelink transmission. In a third submode (e.g., Mode2d), a WTRU may schedule sidelink transmissions for other WTRUs. Thefunctionality associated with the different submodes may be combined(e.g., one submode may be built into another). For example, in Mode 2b,a WTRU may be configured to assist the sidelink resource selection ofother WTRUs.

A WTRU performing V2X communication may utilize a broadcast mechanism atan application (AS) layer. A WTRU engaging in V2X communication may beprovided with an L2 (e.g., layer 2 including a MAC layer) destination ID(e.g., identifier) from upper layers. The L2 destination ID maycorrespond to a V2X service. The WTRU may include the L2 destination IDin the MAC header. Reception may be based on filtering MAC PDUs havingan L2 destination ID matching the services the WTRU may be interestedin.

A WTRU performing V2X communication may utilize unicast and/or groupcasttransmission mechanisms (e.g., when the relevant use case is associatedwith stringent quality requirements such as those in vehicleplatooning). With unicast and/or groupcast, a WTRU may utilize feedbackfrom a receiving device (e.g., HARQ, CQI, etc.) to optimize transmissionpower and/or retransmissions, to allow efficient use of resources andbetter control of quality of service (QoS), etc.

A WTRU may implement one or more QoS models established for V2Xcommunication. For example, the QoS over a communication interface(e.g., such as a PC5 interface) may be supported with ProSe Per-PacketPriority (PPPP). An application layer may be allowed to mark packetswith PPPP, which may indicate a required QoS level. For example, byallowing the derivation of packet delay budget (PDB) based on PPPP,system performance targets may be realized.

Performance indicators and/or design goals associated with QoS mayinclude one or more of payloads (e.g., in terms of bytes), transmissionrates (e.g., in terms of message/sec), maximum end-to-end latency (e.g.,in term of milliseconds), reliability (e.g., in terms of percentage ofsuccess or failure), data rates (e.g., in terms of mbps), or minimumcommunication ranges (e.g., minimum required communication ranges, e.g.,expressed in terms of meters).

In some examples, a common set of service requirements may be applied toV2X communication over different interfaces (e.g., PC5-based V2Xcommunication and/or Uu-based V2X communication).

A unified QoS model may be implemented, e.g., for PC5 and Uu. Forexample, 5G QoS indicators (e.g., 5QIs) may be used for V2Xcommunication over PC5 such that the application layer can have aconsistent way of indicating QoS requirements regardless of the linkused.

There may be multiple (e.g., three) types of traffic for V2X-capableWTRUs. These may include, for example, broadcast, multicast, andunicast. For unicast traffic, the same QoS model as that for Uu can beutilized. For example, each unicast link may be treated as a bearer, andQoS flows may be associated with the unicast link. One or more (e.g.,all) of the QoS characteristics defined in 5QIs and/or one or moreparameters associated with transmission data rates may be applied. Aminimum communication range (e.g., a minimum required communicationrange) may be treated as a parameter specifically for PC5 use.

Similar considerations may be applied to multicast traffic (e.g.,multicast may be treated as a special case of unicast with multipledefined receivers of the traffic).

For broadcast traffic, the concept of bearer may not apply. Each messagemay have different characteristics according to applicationrequirements. 5QIs may be used in a similar manner as for PPPP or ProSePer-Packet Reliability (PPPR). For example, one or more 5QIs may betagged with a packet (e.g., with each packet). 5QIs may represent one ormore (e.g., all) characteristics of a PC5 broadcast operation includinglatency, priority, reliability, etc. A group of V2X broadcast specific5QIs (e.g., VQIs) may be defined for PC5 use.

In examples, V2X QoS requirements may be limited to PPPP and PPPR, whichmay represent latency, priority, and/or reliability requirements. Inexamples, data rate and/or minimum communication range requirements mayalso be supported. Support for these requirements in the context ofnetwork-scheduled operation (e.g., Mode 1 described herein) and/orWTRU-autonomous operation (e.g., Mode 2 described herein) may beconsidered. In network-scheduled operation, the network may have or mayacquire knowledge of the QoS requirements associated with a sidelinkradio bearer (e.g., so as to properly schedule grants). InWTRU-autonomous mode, QoS requirements may be taken into account forcarrier selection and/or reselection.

A WTRU may report the QoS of data available in its buffer for properscheduling by the network (e.g., in network scheduled mode such as Mode1 described herein). A WTRU may have data associated with a differentnumber of QoS or QoS-related parameters, and may report buffer statusrelated to such data to the network. For example, a WTRU may receive afirst type of data associated with only a single QoS parameter (e.g.,PQI-PC5 Quality Indicator), a second type of data associated with twoQoS parameters (e.g., PQI and data rate, PQI and range), and a thirdtype of data associated with three QoS parameters (e.g., PQI, data rate,and range).

Although examples described herein may be explained in terms of V2Xcommunications, these examples and/or embodiments may be more generallyapplicable to other types of communications. For example, they may beapplied to other types of sidelink communications, communications withnetwork-based Radio Access Network (RAN) nodes, and/or other types ofdirect device to device (D2D) communications.

When used herein, data type may refer to data associated with a commonset of one or more QoS parameters. A QoS parameter may indicate one ormore quality characteristics associated with data. A WTRU may receivequality characteristics associated with certain data from an upper layerwhen the data is received in the WTRU's buffers for transmission. Suchquality characteristics may be provided to the WTRU with a (e.g., each)packet from the upper layer. Such quality characteristic may be receivedby the WTRU in association with a flow initiated from the upper layer.For example, the upper layer may initiate a flow and attach a qualitycharacteristic to the flow. The WTRU may receive the qualitycharacteristic in the form of a flow ID with each packet from the upperlayer.

A WTRU may report information related to the QoS of data in the WTRU'sbuffers using a single message or multiple messages. In the case ofmultiple messages, the QoS information may be of different types and/orformats, and may be reported with different frequencies (e.g.,periodicities) and/or triggers. The messages may include an RRC message,a MAC control element (CE) including but not limited to a buffer statusreport (BSR), and/or PHY layer signaling such as a scheduling request(SR) indication on the physical uplink control channel (PUCCH).

A WTRU may use a single message to report QoS information. The messagemay comprise multiple portions (e.g., multiple distinct portions). Forexample, a WTRU may use a MAC CE with multiple information elements(IEs) to report QoS information. The IEs may have different formats andmay include different information, depending on the QoS to be reported.

When referred to here, using a different message (e.g., to report QoSinformation) may include using one or more different IEs (e.g., withdifferent formats) of a message (e.g., to report QoS information).

A WTRU may use a different message to report QoS information of adifferent data type. In examples, a WTRU may report the presence of data(e.g., amount of data, buffer status, initiation of data, etc.) with adifferent message and/or a different message format depending on thedata type. For instance, a WTRU may use a first message or a firstportion of a message (e.g., with a specific format) to report bufferstatus associated with a first data type. The WTRU may use a secondmessage or a second portion of a message (e.g., with a specific formatthat may be different from the format of the first message) to reportbuffer status associated with a second data type.

In examples, a WTRU may report the buffer status of data with one QoSparameter (e.g., PQI) using a first MAC CE (e.g., BSR) and report thebuffer status of data associated with multiple QoS parameters (e.g., PQIand data rate, PQI and range, etc.) with a second MAC CE (e.g., BSR).The WTRU may indicate the message type of a message (e.g., in the formof a MAC CE type, RRC message type, an explicit indication, etc.).

The messages described herein may have different properties or formats.For example, a WTRU may report the buffer status of different data typeswith different BSRs, and the BSRs may be associated with differentlogical channel (LCH) to logical channel group (LCG) mappings. Themessages may use different configurations for LCH-to-LCG mapping. Themessages may be associated with different sets of LCHs and/or differenttypes of LCH-to-LCG mappings.

For example, in a first message, the WTRU may report buffer status for afirst set of LCHs (e.g., those associated with PQI only) based on afirst mapping of LCH to LCG. The WTRU may report a buffer status foreach LCG, for example, by computing the amount of data in all LCHsmapped to that LCG based on a first configuration. In a second message,the WTRU may report the buffer status for a second set of LCHs (e.g.,those associated with PQI and data rate). The second set of LCHs mayhave a different configured LCH-to-LCG mapping.

The messages described herein may be of different types and/or differentformats. For example, a first message may be a MAC CE while a secondmessage may be an RRC message. The messages may use different numbers ofbits to report buffer status for each LCG and/or may use differentnumbers of bits for a destination address (or for any other reportelement). The messages may not all include the same data fields. Forexample, one or more of the messages may not have a certain fieldpresent (e.g., one or more messages may not include an indication ofunicast/groupcast/broadcast or a destination ID).

A WTRU may transmit a first message based on triggers associated with afirst data type and may transmit a second message based on triggersassociated with a second data type. For example, if data arrives at theWTRU for a first data type, and/or the data may be associated with a LCGconfigured for the first data type, the WTRU may report the firstmessage only. If data arrives at the WTRU for a second data type, and/orthe data may be associated with a LCG configured for the second datatype, the WTRU may report the second message only.

A WTRU may use different messages or different parts of a message toreport QoS information (e.g., buffer status) of differentcharacteristics. For example, a WTRU may use a first message to reportinformation related to a first QoS characteristic (e.g., PQI) and asecond message to report information related to a second QoScharacteristic (e.g., range), where a subset of the data associated withthe second QoS characteristic may also be associated with the first QoScharacteristic.

A WTRU may report the buffer status of data (e.g., all data) having atleast one QoS parameter (e.g., PQI) in a MAC CE (e.g., in a BSR). In theexample given above, the WTRU may report, in the second message,information about a subset of data reported in the first message if thesubset of data is also associated with the second QoS characteristic(e.g., range). The second message may include a MAC CE which in turn mayinclude one or more of the following pieces of information.

The MAC CE may include the amount of data associated with the second QoScharacteristic (the amount of data may also be reported in the firstmessage).

The MAC CE may include a specific rule for LCH-to-LCG mapping that isused in the second message, for example, if the WTRU is configured touse multiple LCH-to-LCG mappings and/or QoS-to-LCG mappings and tochoose an appropriate mapping from the configured mappings.

The MAC CE may include the amount of data reported in both the first andsecond message, or the amount of data reported in the second (or first)message that is not reported in the first (or second) message.

The MAC CE may include a specific QoS characteristic (e.g., range, datarate, etc.).

The MAC CE may include a reference or an identifier that identifies thecorresponding first message (e.g., a transaction ID, a time reference,or a message number/message index of the first message).

The MAC CE may include the logical channel group(s) for which the secondmessage is providing information about additional QoS.

The MAC CE may include an explicit or implicit indication of the QoSvalue(s) or range of QoS values associated with the second QoScharacteristic.

A WTRU may report, in a second message, a subset of data previouslyreported in a first message if the subset of data is associated with asecond QoS parameter reported by the second message. For example, a WTRUmay report a first message (e.g., a BSR) which provides buffer statusreport for each LCG configured in terms of a first QoS parameter (e.g.,PQI). The WTRU may be configured with a set of LCHs, wherein each LCHmay be associated with one or more values of the first QoS parameter.The WTRU may be configured with a mapping of the LCHs and one or moreLCGs and/or a mapping between the first QoS parameter and one or moreLCGs. The WTRU may report buffer status for each LCG in the BSR, forexample, by reporting the amount of data associated with the LCHs thatare mapped to the LCG. The WTRU may report in a second message (e.g., inthe form of a MAC CE or by including additional IEs in the BSR) theamount of data available for transmission that was reported in the firstmessage and that is associated with a second QoS parameter (e.g.,range). The WTRU may report the explicit value(s) of the second QoSparameter in the second message.

A WTRU may have data associated with a first QoS parameter (e.g., PQI)only and/or data associated with a first and a second QoS parameters(e.g., PQI and range). The WTRU may use a single message to report BSRfor all of the data, for example by using different IEs to report dataassociated with only PQI and data with both PQI and range. In examples(e.g., for data associated only with PQI), the WTRU may report one ormore of destination, LCG, or buffer status, wherein the LCG maycorrespond to a mapping of PQI to LCG as configured by the network. Inexamples (e.g., for data associated with both PQI and range), the WTRUmay add one or more instances of a range parameter (e.g., which may beassociated buffer status or buffer status percentage). The rangeparameter may include one or more of the following.

The range parameter may include an explicit indication of the rangeparameter (e.g., range in meters) associated with part or all of thedata reported for that LCG.

The range parameter may include an index (e.g., to a configured table)into a set of values of the range parameter that are associated withpart or all of the data reported for that LCG.

A WTRU may indicate, for one or more IEs (e.g., for each IE), the formatof the IE used (e.g., whether a range parameter is included and/or howmany values of the range parameter are include). A WTRU may use anotherfield in the BSR (e.g., a destination index) to indicate the format ofthe IE.

A WTRU may report QoS information based on mappings between differentQoS parameters and LCGs. A WTRU may be configured with a first mappingof a first QoS parameter (e.g., PQI) to one or more LCGs and/or a secondmapping of a second QoS parameter (e.g., data rate) to one or more LCGs.The WTRU may report, in a first message, the amount of data associatedto each LCG of the first mapping. The WTRU may report, in a secondmessage, the amount of data associated to each LCG of the secondmapping. The WTRU may report (e.g., in a first message, in a secondmessage, or in a different message other than the first or secondmessage) the amount of data that may be associated to a specific LCG andthat may have already been reported in both a first message and a secondmessage. The WTRU may report (e.g., in a first message, in a secondmessage, or in a different message other than the first or secondmessage) the total amount of data in the WTRU's buffer.

A WTRU may report QoS information based on a multiple-stageconfiguration associated with QoS parameters and/or LCGs (e.g., in amulti-stage BSR). A WTRU may be configured to report QoS relatedinformation (e.g., buffer status) for a set of configured logicalchannel groups in multiple stages whereby the configuration of a LCG maynot necessarily depend on an actual QoS parameter. For example, a WTRUmay be configured with a number of LCGs, where each LCG may be tied toone or more QoS characteristics (e.g., PQI, rate, range, etc.).

In a first stage, the WTRU may report QoS information (e.g., bufferstatus) associated with one or more subsets of LCGs. The WTRU may reportQoS information (e.g., a buffer status) associated with a subset of oneor more LCGs if any LCH belonging to the LCG(s) have data available inthe buffer. In a second stage, the WTRU may report QoS information(e.g., buffer status) associated with each LCG or only those LCGs forwhich buffer status was reported in a corresponding subset of LCG(s)during the first stage.

The QoS information reported in a stage may be in the form of one ormore of a LCG (e.g., in terms of an index), a LCG subset (e.g., in termsof an index) whereby each LCG subset index may identify a set of indexedLCGs, an actual amount of data in the WTRU's buffers that correspond toa LCG or a subset of LCGs, an indication that some data is available fortransmission in a LCG or a subset of LCGs (e.g., the WTRU may reportbuffer status for a LCG as a percentage of the buffer status reported ina previous message), a percentage of a total amount of data where thetotal amount of data may be reported separately or in a different stage,or any other QoS related information discussed herein.

A WTU may report buffer status associated with a (e.g., each) subset ofLCGs in a first stage, and may report, in a second stage, a percentageof the buffer status (e.g., relative to the buffer status reported inthe first stage) for each LCG in a subset of LCGs.

A WTRU may be configured, e.g., by the network, with a mapping of QoS toLCG(s) and/or a mapping of LCG(s) to LCG subset(s). Such configurationmay be in the form of an RRC configuration, a MAC CE, or anothersuitable form. For example, a WTRU may be configured with a mapping ofone or more QoS parameters to one or more LCGs. The mapping may indicatedata associated with at least one QoS parameter (e.g., LCG 1=all dataassociated with PQI1, PQI2, and/or PQI3, regardless of the values ofother QoS parameters or whether such data is associated with the otherQoS parameters). The mapping may indicate data associated with multipleQoS parameters (e.g., LCG 1=all data associated with PQI1 and data ratev1).

A WTRU may be configured with a mapping of one or more LCGs to one ormore LCG subsets. For example, a WTRU may be configured with 64 LCGs.The WTRU may be further configured to map LCG 1-8 to LCG subset 1, LCG9-16 to LCG subset 2, and so on.

A WTRU may be configured with multiple mappings and may change from onemapping to another based on a network indication. For example, the WTRUmay receive a set of configurations from the network (e.g., via RRC) andmay switch from one configuration to another configuration upon receiptof a MAC CE.

A WTRU may autonomously change QoS to LCG mapping and/or LCG to LCGsubset mapping. A WTRU may change (e.g., switch from one to another)among a subset of preconfigured mappings (e.g., as provided by thenetwork). A WTRU may indicate a selected mapping to the network, e.g.,as part of the signaling performed by the WTRU in a first stage. A WTRUmay change a mapping based on one or more of the following.

A WTRU may change a mapping in response to new data arriving in theWTRU's buffers and/or based on current data in the WTRU's buffers. Forexample, a WTRU may determine, based on the data available fortransmission, the mapping of QoS to LCG(s) and/or LCG(s) to LCGsubset(s) to minimize the amount of information to be sent in accordancewith the number of LCG subsets or the number of LCGs for which bufferstatus is to be reported and/or in accordance with the size of a report(e.g., a BSR).

A WTRU may change a mapping based on the size of a grant from thenetwork. For example, a WTRU may select a configuration of QoS to LCG(s)and/or LCG(s) to LCG subset(s) so that a corresponding report of QoSinformation (e.g., during a first stage and/or a second stage asdescribed herein) may be transmitted using a corresponding grant fromthe network.

A WTRU may change a mapping based on the conditions of a sidelink (SL)channel. For example, a WTRU may select a configuration of QoS to LCG(s)and/or LCG(s) to LCG subset(s) based on current measurements of constantbit rate (CBR), SL HARQ feedback, SL channel state information (CSI), SLradio resource management (RRM), and/or other similar SL measurements.The WTRU may provide a preliminary mapping of QoS to LCG(s) underconditions where QoS parameter(s) can be met (e.g., low CBR) and mayprovide a finer mapping of QoS to LCG(s) under conditions where QoSparameter(s) may be more difficult to meet (e.g., high CBR).

A WTRU may be configured with multiple destination indices (e.g., forconveying buffer status information with different QoS characteristicsto a destination). For example, a WTRU may be configured with multipledestination indices for a single destination address (e.g., a V2X L2destination ID), and may use the different destination indices to reportdifferent sets of QoS information and/or buffer status.

For example, a WTRU may be configured with two destination indices(e.g., D1 and D2) associated with the same destination address (e.g., anL2 destination ID). The WTRU may report, to the destination, the amountof data available for transmission that is associated with a first QoSparameter (e.g., PQI) using D1 in a BSR. The WTRU may report, to thedestination, the amount of data available for transmission that isassociated with a second QoS parameter (e.g., data rate) using D2 in aBSR.

Mode 2 transmission (e.g., autonomous transmission) may be supported. Anassociated data rate may be computed, selected, and/or reselected.

A WTRU may select an amount of resources and/or one or more carriersbased on data rate requirements such as a data rate requirementassociated with a transmission. The transmission may comprise one ormore PDU(s) or packet(s) to be transmitted, one or more logicalchannels, one or more sidelink radio bearers (SLRBs), one or moresidelink processes, a number of transmissions associated with periodicdata at the WTRU, and/or transmissions associated with aperiodic (e.g.,one-shot) transmission at the WTRU.

A WTRU selecting the number of resources and/or carriers based on arelevant data rate may comprise the WTRU selecting one or more of thefollowing.

The WTRU may select a minimum, maximum, and/or average number oftime/frequency resources (e.g., subchannels) to be used to perform atransmission, e.g., over a configured time period.

The WTRU may select a minimum, maximum, and/or average number ofcarriers, bandwidth parts (BWPs), and/or beams to be used to perform thetransmission.

The WTRU may select a minimum, maximum, and/or average number ofsidelink processes used to perform the transmission.

The WTRU may select a minimum, maximum, and/or average number of times(e.g., successive times) the WTRU can re-use a resource (e.g., areserved resource) before performing a procedure associated with theacquisition of the resources (e.g., resource selection based onsensing).

The WTRU may select a minimum, maximum, and/or average number offrequency resources.

The WTRU may select a minimum, maximum, and/or average number ofperiodicities. Either or both of these selections may be associated withone or more periodic sidelink processes.

A WTRU may select a number of resources and/or carriers based onachievable data rates of the resources and/or carriers (e.g., asdetermined by the WTRU using associated CSI reporting). For example, aWTRU may determine a range of achievable data rates based on CQIassociated with the resources and/or carriers over a configured (e.g.,preconfigured) period. A WTRU may determine a range of achievable datarates based on the transport block size (TBS) configured (e.g.,pre-configured) for one or more CQI values (e.g., for each CQI value).

The range of achievable data rates as described herein may include oneor more of a minimum data rate, a maximum data rate, an average datarate, or an x-percentile data rate. An x-percentile data rate may referto a data rate higher than x % of all determined data rates. Forexample, a median data rate may refer to a 50-percentile data rate.

A WTRU may determine its data rate requirements at a given time based onthe number or set of active or configured SLRBs at the WTRU. A WTRU maydetermine its data rate requirements at a given time based on respectivedata rates associated with one or more SLRBs or logical channels (e.g.,a data rate associated with each SLRB or logical channel) at the WTRU.

A WTRU may determine its data rate requirements based on the prioritizedbit rate (PBR) and/or a higher layer rate-related parameter (e.g., suchas a guaranteed bit rate or GBR) configured (e.g., preconfigured) forany or all of the configured or active SLRBs at the WTRU. For example, aWTRU may determine its required data rate as the sum of data rates ofone or more (e.g., all) established (e.g., active) SLRBs associated witha GBR. Alternatively or additionally, a WTRU may be configured withrespective data rate parameters for one or more SLRBs (e.g., a data rateparameter for each SLRB) and may use the sum of such data rates acrossthe SLRBs.

The selection of resources described herein may be in the form of aratio of resource, carriers, BWPs, and/or beams utilized by a WTRU overthe total number of available resources, carriers, BWPs, and/or beams.For example, a WTRU may be configured with a maximum occupancy ratioassociated with a set of SLRBs based on the data rates or aggregateddata rates of the SLRBs.

The determination of the amount of resources from the data raterequirements for a transmission may be based on one or more configuredor pre-configured rules. Such rule(s) may depend on other QoSrequirements of the data, such as latency, priority, minimumcommunication range, and/or reliability. For example, a WTRU may beconfigured with a different number of resources and/or carriers to beused for a specific data rate requirement depending on the priority,latency, reliability and/or communication range of the data and/or CBR.

A WTRU may determine the number of allowable sidelink processes on acarrier based on the aggregated data rate of the SLRBs operating on thatcarrier.

A WTRU may determine the number of periodic time, frequency, and/or beamresources associated with a sidelink process that can be reserved duringa resource selection procedure based on the aggregated data rate of theSLRBs mapped to that sidelink process. The number of time, frequency,and/or beam resources associated with a sidelink process that can bereserved may comprise the number of periods for which resources can bereserved without resource reselection.

A WTRU may determine the number of allowable (e.g., maximum) subchannelsthat can be selected by the WTRU (e.g., for a single transmission of asidelink process associated with one or more SLRBs) based on theaggregated data rate of SLRBs mapped to such transmission. A WTRU may beconfigured with a maximum number of time/frequency resources (e.g.,subchannels) that can be used by the WTRU over a fixed or configured(e.g., pre-configured) time window. The WTRU may select individualtransmissions and/or SL processes within that time window such that thetotal number of resources selected within the window may not exceed amaximum associated with the aggregated data rate of the concerned SLRBs.

A WTRU may determine the number of allowed carriers for multicarriertransmission based on the aggregated data rate of the SLRBs associatedwith WTRU.

A WTRU may determine the maximum number of resources it can select ortransmit on for a particular slot or group of slots, such as, forexample, a channel occupancy ratio (CR) limit.

A WTRU may reserve and/or select resources in accordance with a maximumrate of resources (e.g., up to a maximum rate of resources). Theresources may be reserved or selected resources. A rate of resources asdescribed herein may correspond to an amount of resources selected orreserved per time interval. The time interval may be predefined (e.g.,configured) by the network and/or the WTRU.

At a given time, a WTRU may be configured with or may determine amaximum amount of time/frequency resources that the WTRU may select orreserve over a configured time period such that the WTRU may comply witha maximum rate of selected resources. A WTRU may autonomously select orreserve a (e.g., any) number of time/frequency resources that can beused to transmit the data in the WTRU's buffers as long as the WTRU doesnot exceed a maximum rate of selected resources. Such rate of selectedresources can be derived, e.g., based on the data rate requirementassociated with one, multiple or all SLRBs (e.g., which may beassociated with mode 2 transmissions).

A WTRU may select a number of resources (e.g., resources associated withone or more sidelink processes) that comply with a maximum rate ofselected resources. For example, a WTRU may perform resource selectionfor one or multiple periodic sidelink processes such that the resultingrate of resources selected or reserved by the WTRU (e.g., the amount ofresources per time interval) is less than or equal to a maximum rate ofselected resources.

A WTRU may determine its current rate of selected resources bydetermining the total amount of resources selected for one or more(e.g., for all) of its sidelink processes. For example, for periodicsidelink processes, the WTRU may determine the rate of selectedresources as the sum of the number of resources per time interval usingthe periodicity and size of reserved resources for one or more (e.g.,for all) of the processes. In examples (e.g., for aperiodic sidelinkprocesses), the WTRU may maintain a count of the number of asynchronousresources selected over a time window and calculate the rate of selectedresources for this process based on the count and/or length of the timewindow.

A WTRU may use a combination of one or more of the following factors(e.g., in addition to or in lieu of rate requirements) to determine themaximum rate of selected/reserved resources.

A WTRU may use measured congestion of a resource pool (e.g., asindicated by a channel busy ratio or CBR) to determine the maximum rateof selected/reserved resources. For example, a WTRU may be configured(e.g., preconfigured) with a mapping between CBR range, total data raterequirement (e.g., over all SLRBs), and maximum rate of selectedresources. The WTRU may determine its maximum rate of selected resourcesbased on the measured CBR, the total rate requirement among the SLRBsconfigured or active at the WTRU, and the configured mapping.

A WTRU may use the QoS requirements of the WTRU's configured or activeSLRB(s) to determine the maximum rate of selected/reserved resources.The QoS requirements may include priority, latency, reliability,communication range and/or other parameters in addition to or in lieu ofdata rate. For example, the WTRU may determine the number of SLRBshaving priority, reliability, and/or rate higher than a configured(e.g., preconfigured) threshold and may determine the maximum rate ofselected resources based on the number of such SLRBs. The WTRU may beallowed to increase its allowed rate of selected resources (e.g.,relative to a default calculated amount) by a certain amount for a SLRBhaving priority, reliability, and/or rate larger than a threshold. TheWTRU may increase or decrease the data rate requirement configured for aSLRB by a factor (e.g., the value of the factor may depend on a QoSparameter).

A WTRU may use allowed or configured maximum transmit power at the WTRUto determine the maximum rate of selected/reserved resources. Forexample, the WTRU may scale its allowed rate of selected resources up ordown depending on the configured or allowed maximum transmit power atthe WTRU.

A WTRU may use the MCS associated with a sidelink to determine themaximum rate of selected/reserved resources. For example, the WTRU maydetermine a maximum or target MCS to be used for sidelink transmissions.Such MCS may depend on one or more other factors described herein (e.g.,such as the transmission speed of the WTRU). Such MCS may be derivedbased on channel measurements (e.g., such as CQI for the case ofunicast). The WTRU may scale the maximum rate of selected resourcesbased on the MCS to be used for sidelink transmissions.

A WTRU may use a computed value of an achievable data rate on a givencarrier or for a specific selected (e.g., configured) MCS (e.g., asdescribed herein) to determine the maximum rate of selected/reservedresources.

A WTRU may use its transmission speed to determine the maximum rate ofselected/reserved resources. For example, the WTRU may increase ordecrease its computed maximum rate of selected resources based onchanges in the WTRU's transmission speed.

A WTRU may be allowed to exceed (e.g., temporarily exceed) a maximumrate of selected resources under certain conditions. For example, a WTRUmay be allowed to temporarily exceed the maximum rate of selectedresources based on a combination of one or more of the following.

A WTRU may be allowed to temporarily exceed a maximum rate of selectedresources if the measured channel busy ratio is below a threshold.

A WTRU may be allowed to temporarily exceed a maximum rate of selectedresources due to QoS requirements. For example, a WTRU may be allowed totemporarily exceed a maximum rate of selected resources if the maximumrate of reserved resources cannot satisfy the QoS requirements (e.g.,latency, rate, etc.) of data buffered by the WTRU.

A WTRU may be allowed to temporarily exceed a maximum rate of selectedresources when asynchronous data transmission is triggered (e.g., if theWTRU decides to initiate an asynchronous sidelink process).

A WTRU may be allowed to temporarily exceed a maximum rate of selectedresources in accordance with the number of activated or initiated SLRBsmeeting certain QoS requirements (e.g., in response to the number ofsuch SLRBs exceeding a threshold).

A WTRU may be allowed to temporarily exceed a maximum rate of selectedresources when data becomes available or buffered for one or more SLRBsmeeting certain QoS requirements.

A WTRU may be allowed to exceed the maximum rate of selected resourcesfor a period of time. Such a period of time may be configured (e.g.preconfigured), for example, by a network. For instance, a WTRU mayinitiate a timer at an event that triggers the WTRU to exceed thedetermined maximum rate of selected resources (e.g., as describedabove). The WTRU may continue to exceed the rate until the timerexpires. A WTRU may be allowed to exceed the maximum rate of selectedresources for a configured (e.g., preconfigured) number of periods of aSL process. A WTRU may be allowed to exceed the maximum rate of selectedresources during one or more consecutive time windows (e.g., timeperiods). A WTRU may be configured with such time windows by a network.A WTRU may be configured to exceed the maximum rate of selectedresources once every N time windows (e.g., at most once every N timewindows). A WTRU may be allowed to initiate a sidelink process thatwould result in the WTRU exceeding the maximum rate of selectedresources if one or more conditions (e.g., the conditions of CBR and/orQoS requirements as described herein) are satisfied. For example, if ameasured CBR is below a threshold, and the WTRU initiates and/or hasdata for a number of SLRBs, the WTRU may initiate a new SL processand/or may perform resource reselection of a SL process. These SLRBs maynot be configured with a rate-related requirement but may have apriority or latency related parameter that meets certain conditions(e.g., preconfigured conditions).

A WTRU may be configured with resource selection parameters for a SLprocess. These parameters may be different depending on whether they areassociated with an event that triggers the WTRU to exceed the maximumrate of selected resources or whether they may cause the WTRU to exceedthe maximum rate of selected resources.

A WTRU may use a different (e.g. a shorter or smaller) value of thereselection counter for such a SL process. A WTRU may use a differentrule (e.g., in accordance with whether CBR is below a threshold) whendeciding whether it can perform resource reselection for such a SLprocess.

A WTRU may differentiate GBR and non-GBR SLRBs in a flow-to-SLRB mappingand/or in rate computation. A WTRU may be configured with a SLRB of afirst type, which may allow rate enforcement, and a SLRB of a secondtype, which may not allow rate enforcement. The WTRU may determine theSLRB type based on the presence or absence of a rate-related parameter.For example, a SLRB with a configured rate-related parameter may beconsidered a SLRB with rate enforcement. A SLRB with a PBR greater thanzero may be considered a SLRB with rate enforcement. A SLRB with a PBRequal to zero may be considered a SLRB without rate enforcement.

A WTRU may determine the maximum rate of selected resources by acombination of rate-related parameters that may be configured (e.g.,preconfigured) for one or more SLRBs (e.g. for each SLRB). A WTRU mayconsider only SLRBs that allow rate enforcement in the calculation ofthe total rate of selected resources.

A WTRU may be configured with a soft and/or a hard data raterequirement. The data rate requirement may be associated with a specificSLRB. For example, a WTRU may be configured with a hard data raterequirement for one SLRB (e.g., a SLRB having rate enforcement) and asoft data rate requirement for another SLRB (e.g., a SLRB not havingrate enforcement). A WTRU may be configured (e.g., preconfigured) withan indication of whether a SLRB data rate requirement is a soft datarate requirement or a hard data rate requirement. A WTRU may determinethe total rate of selected resources by treating hard and soft data raterequirements differently.

A SLRB with a soft data rate requirement may be given a different (e.g.,smaller) weight than an SLRB with a hard data rate requirement duringthe computation of maximum rate of selected resources.

A SLRB with a soft data rate requirement may be ignored in thecalculation of the rate of selected resources under certain conditions.The conditions may be associated with (e.g., may depend on) CBR, sensingresults, channel quality, etc.

A WTRU may determine the maximum rate of selected resources based onrates attached to one or more SLRBs configured with rate enforcement. AWTRU may add a configured (e.g., preconfigured) or calculated amount oroffset to the total rate of SLRBs not configured with rate enforcement.The value of such an offset may depend on QoS parameters in a SLRBconfiguration, CBR, channel quality, speed, network indication (e.g.,which may be used to dynamically enable or disable the offset),coverage, etc.

A WTRU may restrict and/or prioritize a subset of SLRBs to use aspecific SL process or carrier.

A WTRU may associate a subset of SLRBs with a specific sidelink processor carrier, e.g., based on one or more configured restrictions. Inexamples, the WTRU may perform sidelink resource selection for aperiodic sidelink process in which the sidelink process may be useablefor (e.g., only usable for) or may be prioritized for use with a subsetof SLRBs. Rules for the restriction and/or prioritization of SLRBs maybe determined based on one or more of the following factors.

The restriction and/or prioritization of SLRBs with a SL process orcarrier may be based on a configured periodicity of a SLRB. For example,a WTRU may be configured to map SLRBs associated with a subset ofperiodicities onto a SL process selected with a specific periodicity.

The restriction and/or prioritization of SLRBs with a SL process orcarrier may be based on a minimum communication range requirement. Forexample, a WTRU may select resources for a sidelink process associatedwith a specific minimum communication range (MCR) or a set of minimumcommunication ranges (MCRs). The selection of such resources to satisfya minimum communication range may follow the examples described herein.Once selected, the sidelink process may be utilized by the WTRU for(e.g., only for) the SLRBs associated with the minimum communicationrange or the set of minimum communication ranges.

The restriction and/or prioritization of SLRBs with a SL process orcarrier may be based on a cast type. For example, a WTRU may selectresources for a periodic sidelink process associated only with aspecific cast type (e.g., unicast, groupcast, or broadcast).

The restriction and/or prioritization of SLRBs with a SL process orcarrier may be based on priority and/or latency related QoS parameter(s)configured by an upper layer. For example, a WTRU may be configured witha priority associated with one or more SLRBs (e.g., with each SLRB). TheWTRU may perform resource selection for a sidelink process (e.g., aperiodic sidelink process) associated with a specific priority or arange of priorities. The WTRU may allow (e.g., only allow) SLRBsassociated with the priority or priorities to be used in that SLprocess.

A WTRU may enforce the restriction for a sidelink processes during a LCPprocedure. In such a procedure, a grant for a specific sidelink processmay allow (e.g., only allow) or prioritize the use of certain LCHsassociated with a specific periodicity, range, cast type, priority, etc.

A WTRU may consider restrictions associated with logical channels and/orSLRBs mapped to a sidelink process and/or carrier when determining theamount of resources, processes, and/or carriers to be selected. Forexample, a WTRU may select a maximum, a minimum or an average number ofresources associated with a periodic sidelink process based on the totalPBR configured for the SLRBs that are allowed to be mapped to thatspecific sidelink process.

A WTRU may maintain different sidelink process types and computeselected resources separately for each type.

A WTRU may maintain one or multiple sidelink processes of differenttypes. A WTRU may be allowed to transmit data on a specific sidelinkprocess type only for certain logical channels. For example, a SLRB maybe associated with (e.g., only with) sidelink processes of one or moretypes. A sidelink process of a specific type may be associated with(e.g., allowed to carry data from a logical channel of) one or more ofthe following.

A sidelink process of a specific type may be associated with certain QoSrequirements. Such QoS requirements may include, for example, range ofpriority, latency, minimum communication range, data rate, reliability,and/or the like. A sidelink process of a specific type may be used inaccordance with the presence or absence of such QoS requirements orassociated parameter(s) in a LCH configuration.

A sidelink process of a specific type may be associated with a cast type(e.g., unicast, groupcast, or broadcast).

A sidelink process of a specific type may be associated with a PHY layerconfiguration. For example, a SL process may be associated with aspecific PHY layer configuration such as a specific type of HARQconfiguration (e.g., having HARQ enabled or disabled), a specific typeof RLM/RLF configuration, a specific type of CQI measurementconfiguration (e.g., reference signal density, feedback frequency,etc.), and/or the like.

A WTRU may determine a maximum rate of selected resources separately foreach sidelink process type. A WTRU may determine the maximum rate ofselected resources in accordance with the SLRBs configured for thatsidelink process type (e.g., according to the examples describedherein). A WTRU may be configured with different rules for computing themaximum rate of selected resources, for example, depending on thesidelink process type.

A WTRU may use different rules (e.g., two different rules) fordetermining the number of resources, for example, depending on raterequirements. A WTRU may select an amount of resources based on whetherthe final amount of selected resources is above or below a threshold.The threshold may be determined, e.g., based on the data raterequirement of the transmission.

A WTRU may select an initial number of resources determined by the datarate requirement for a transmission (e.g., based on configured orpre-configured mapping of data rate requirement to resource amount). TheWTRU may select additional resources beyond this initial amount ofresources based on a mapping of CBR and/or priority to a maximum numberof resources.

A WTRU may select one or more carriers for transmission based on arequisite transmission data rate. For example, a WTRU may select one ormore carriers for a transmission (e.g., a transmission as definedherein) with an associated data rate based on measurements (e.g.,sensing) of the resources on that carrier. The selection of such acarrier may be based on a determination that the carrier can support therequired data rate. The selection of such a carrier may be made to avoidimpact of the WTRU's own data rate on that of other WTRU(s) operating onthe carrier. The selection of such a carrier may be based on acombination of the foregoing two factors. For example, a WTRU may beconfigured with specific rule(s) to determine whether a carrier can beselected/used for a transmission based on the data rate requirements ofa transmission and the sensing/measurement results of an associatedcarrier, as described herein.

A WTRU may select one or more carriers that can meet the requirements ofan associated data rate based on measurements that indicate that such adata rate can be supported.

A WTRU may select a carrier based on measurements that indicate that anassociated data rate can be met with the available resources. Forexample, a WTRU may select a carrier based on one or more of thefollowing measurements on the carrier.

The WTRU may select a carrier based on resource occupancy on thatcarrier (e.g., based on a channel busy ratio or CBR). The WTRU mayselect a carrier based on the ratio of reserved/available resources overa future time period, whereby such a future time period may depend on aQoS characteristic of the transmission. The WTRU may select a carrierbased on a measured number/ratio of available resources that maycomprise a certain number of contiguous (e.g., in time and/or frequency)resources. For example, the WTRU may measure the ratio of availableresources that have at least x contiguous subchannels associated withthem. The value of x may be configurable. The WTRU may select a carrierbased on CSI associated with the resources of the carrier.

In examples (e.g., when a WTRU has a transmission associated with one ormore SLRBs with a data rate of x), a WTRU may select a carrier for thetransmission if the ratio of available resources (e.g., as indicated bysensing/measurement results) on that carrier is at least y. The WTRU maybe configured, for example, with a table that maps the values of x to y.

In examples (e.g., when a WTRU has a transmission associated with one ormore SLRBs with a data rate of x), a WTRU may select a carrier for thetransmission if the SLRB(s) have a measured CBR that is below aconfigured threshold. The threshold may depend on x.

A WTRU may selects one or more carriers to avoid impacting other WTRUs.A WTRU may select a carrier based on QoS measurements of other WTRUsthat may be detected on that carrier. Such detection may be performed,for example, based on (e.g., by decoding) sidelink control information(SCI) transmitted by the other WTRUs announcing future transmissions.The WTRU may select the carrier(s) such that high rate transmissions maynot impact other WTRUs that also use the carrier. The WTRU may use acombination of criteria to select/not select a carrier for atransmission. A configured parameter in the criteria may depend on therelevant data rate. For example, the WTRU may select a carrier based ona configured number of WTRUs having QoS parameter(s) that meetpre-configured criteria (e.g., detection of at least x WTRUs havinglatency/priority of transmission smaller than a value of y).

A WTRU may be configured to perform carrier/resource reselection basedon one or more rate-related triggers (e.g., triggers related to the rateof transmission). For example, such triggers may be based on the WTRUdetermining that attempts to meet the rate requirements associated witha transmission have failed. The triggers may include one or more of thefollowing.

The triggers may include a change in the measurement of achievable datarates on a carrier. For example, a WTRU may perform carrier/resourcereselection when it determines that the achievable data rate on acarrier on which the WTRU is performing a rate-related transmission hasfallen below a threshold or has been reduced by a certain threshold. AWTRU may perform carrier/resource reselection when it determines thatthe achievable data rate on a carrier has changed by at least a certainamount from an initial value (e.g., an initial value determined at SLRBestablishment or modification). Such an initial amount may be determinedbased on a configuration and/or the value of the achievable data rateitself. A WTRU may perform carrier/resource reselection when itdetermines that the difference between the achievable data rate and thetotal required data rate of one or more (e.g., all) SLRBs has changed bya certain amount.

The triggers may include a change in the number of active transmissions(e.g., SLRBs) associated with a rate requirement. The triggers may bebased on that a computed aggregated transmission rate requirement haschanged by a certain amount. For example, a WTRU may performcarrier/resource reselection following the initiation of a SLRB having aspecific rate requirement.

The triggers may include a change in the measured quality of carrier(s)and/or resource(s) used by a WTRU to perform transmissions (e.g.,transmission having a certain associated data rate). For example, a WTRUmay perform carrier/resource reselection following a determination thatthe measured and/or reported quality of a set of resources has changedby a certain amount.

The triggers may include a change in the profile of QoS properties beingused by other WTRUs (e.g., as detected via sensing/measurement). Forexample, a trigger may be based on a change in the number of WTRUshaving certain QoS properties on the carrier exceeding a certain amount.

The triggers may include a failure or error condition detected during aLCP procedure. For example, a WTRU may determine that the number ofresources associated with one or multiple sidelink processes is toolarge or too small to satisfy the data rate requirements of a set ofSLRBs. The WTRU may make such a determination based on the results of aLCP procedure applied to the grants of the one or multiple sidelinkprocesses. The WTRU may make such a determination based on the amount ofdata in a buffer associated with a LCH (e.g., a LCH explicitlyconfigured with a data rate requirement). The WTRU may perform resourcereselection when one or more of the following are satisfied.

The WTRU may perform resource reselection when the value of a bucket orbuffer size parameter (e.g., Bj or a similar bucket or buffer sizeparameter) associated with one or more LCHs remains positive or negativefor a configured or predefined period of time.

When referred to herein, the terms bucket size may represent an amountof data to be transmitted (e.g., at an instance of channelprioritization, such as logical channel prioritization). For example,the term bucket size may represent the amount of data to be transmitted(e.g., at an instance of logical channel prioritization) for a givenlogical channel (e.g., logical channel j), for example, to meet a bitrate requirement (e.g., prioritized bit rate requirements) of thatlogical channel. Bj may represent a bucket size for a channel j (e.g.,logical channel j). In examples, the bucket size or Bj (e.g., forlogical channel j) may be determined based on a prioritized bit rate(PBR) and a bucket size duration (BSD) associated with the logicalchannel (e.g., based on the product of PBR and BSD, or PBR x BSD). Thevalue of bucket size or Bj may change with time, for example, as dataassociated with the logical channel is transmitted using a grant. Inexamples, Bj>0 at a given time may indicate that there is prioritizeddata in a bucket of the logical channel and/or that a grant should beused to transmit the prioritized data for the logical channel (e.g., inorder to meet a data rate requirement for the logical channel). Bj<=0may indicate that a data rate requirement associated with the logicalchannel has been satisfied.

The WTRU may perform resource reselection when the value of a bucketsize parameter (e.g., Bj or a similar bucket size parameter) associatedwith one or more LCHs exceeds or is smaller than a configured orpredefined threshold.

The WTRU may perform resource reselection when the value of a bucketsize parameter (e.g., Bj or a similar bucket size parameter) for one ormore logical channels has increased over a configured or predefinednumber of LCP procedures or over a preconfigured or predefined timewindow.

The WTRU may perform resource reselection when the amount of increase ina bucket size parameter (e.g., Bj or a similar bucket size parameter)observed over a number of LCP procedures or over a time window is largerthan a configured or predefined amount.

The WTRU may perform resource reselection when pending data from one ormore SL logical channels is not included in any SL grant for aconfigured or predefined period of time.

The WTRU may perform resource reselection when the amount of data in thebuffers associated with one or more logical channels (e.g., one or morelogical channels associated with a specific data rate requirement)exceeds a threshold. The threshold may be based on or may be derivedfrom one or more of a configuration or predetermination, a configuredLCP parameter such as PBR, BSR, etc. for the one or more logicalchannels, the current size of the grant(s) associated with one or moreconfigured SL processes, the period (e.g., time between successivegrants) of one or more SL processes, the maximum allowable size of agrant (e.g., a one-time grant or periodic grants), the number ofsubchannels in a BWP and/or a carrier or the number of subchannels in aset of BWPs and/or carriers, a measured CBR, or a CQI report from a peerWTRU for a unicast or groupcast link.

A WTRU may perform resource reselection if the amount of data in one ormore buffers of a logical channel is larger than k*PBR*BSD, where k maybe configured or predetermined (e.g., by the network) and BSD (bucketsize duration) may indicate the amount of time during which dataassociated with a logical channel is buffered at the PBR (prioritizedbit rate) until a bucket size associated with the logical channel isreached.

A WTRU may perform resource reselection if the amount of data in one ormore buffers of a logical channel is larger than k*M*PBR, where M mayrepresent the total grant sizes of one or more (e.g., all) pending SLgrants or processes divided by the total number of logical channels, andk may be configured or predetermined (e.g., by the network).

A WTRU may perform resource reselection if the PBR for a LCH is largerthan k*M*f, where M may represent the total or average grant size of oneor more periodic SL processes, f may represent the average frequency ofone or more SL processes (e.g., how often they occur), and k mayrepresent a configured or predetermined parameter (e.g., by thenetwork).

A WTRU may determine the SL process on which the WTRU may performresource reselection. A WTRU may perform resource reselection on one ora subset of SL processes following a data rate related reselectiontrigger. A WTRU may select the one or more SL processes on whichresource reselection is performed (e.g., out of a set of configured SLprocesses) based on one or more of the following rules.

The WTRU may select the SL process(es) with the smallest or largestgrant size, or whose grant size has been configured to be associatedwith the QoS parameters configured for a LCH.

The WTRU may select the SL process whose next configured grant occursfirst with respect to a trigger for resource reselection.

The WTRU may select the SL process with the shortest/largestperiodicity, or whose periodicity has been configured to be associatedwith the QoS parameters configured for a LCH.

The WTRU may select the SL process that respects (e.g., complies with) amapping restriction or mapping preference between logical channels andSL processes. The mapping restriction or preference may be based on theperiodicity of traffic associated with a LCH and/or the periodicity ofthe SL process.

The WTRU may select a SL process such that any increase or decrease inthe size of the grant associated with the SL process may not result inthe WTRU exceeding the maximum configured grant size of the SL processor falling below the minimum configured grant size of the SL process.

The WTRU may select the SL process that was initiated by the WTRU as aresult of the initiation of a LCH or SLRB.

The WTRU may select the SL process whose reselection counter is thesmallest or the largest.

A WTRU may select one or more SL processes (e.g., any SL process) towhich the LCH that triggered reselection can be mapped. Such mapping maybe configured based on the latency associated with the LCH configurationand/or the corresponding periodicities of the one or more SL processes.

A WTRU may trigger resource reselection on multiple SL processes inresponse to one or more (e.g., any) of the rate-related triggersdescribed herein. For example, a WTRU may determine that performingresource reselection on one sidelink process may cause the WTRU toexceed the maximum reserved/selected data rate. In such case, the WTRUmay select one or more other SL processes and perform resourcereselection in order to reduce the total amount of reserved/selectedresources to be below the maximum reserved/selected data rate. The WTRUmay select one or more SL processes associated with the least stringentQoS requirements (e.g., lowest priority) if such an association exists.The WTRU may select one or more SL processes with the largest currentreselection counter.

A WTRU may determine whether to maintain reserved resources and theamount of time during which such resources are maintained based on oneor more QoS parameters. The WTRU may decide the amount of time formaintaining these reserved resources for a sidelink process based onfactors associated with the QoS requirements of one or more SLRBs mappedto the sidelink process. The WTRU may determine the number of periods(e.g., which may correspond to an amount of time) during which aresource should be reserved based on one or more of data rate relatedparameters, latency related parameters, minimum communication relatedparameters, a random number selected by the WTRU, a preconfigured valueor factor, congestion related parameters (e.g., such as a channel busyratio), or cast(s) of the SLRBs that are currently operating.

A WTRU may determine a time period during which a set of resources canbe reserved for a sidelink process. A WTRU may determine the number oftimes a set of reserved resources can be repeated for a sidelinkprocess. A WTRU may perform either or both of the foregoingdeterminations during a resource selection procedure for the sidelinkprocess. A WTRU may perform either or both of the foregoingdeterminations based on a total maximum rate of reserved resources. AWTRU may be configured with a mapping between a computed maximum rate ofreserved resources and a number of repetitions for a SL process. Forexample, a WTRU may be configured with a mapping between a maximum rate,a CBR, and/or a number of resources that can be reserved during aresource selection procedure for a SL process.

A WTRU may decide whether it can perform resource reselection for asidelink process based on one or more (e.g., any) of the factorsdescribed herein. For example, a WTRU may determine, at the time ofresource reselection for one or more SL processes, whether it canreserve resources for a sidelink process based on whether a measured CBRis above or below a configured threshold.

Resource and/or carrier selection/reselection may be performed forunicast communication. For unicast communication, resources may besynchronized between multiple (e.g., two) WTRUs, for example, to avoidhalf-duplex issues between the WTRUs. A carrier may be synchronized,e.g., since a WTRU may transmit HARQ feedback for another WTRU'stransmissions and the data and HARQ feedback may be on the same carrier.

The following may apply to carriers (e.g., in the context of a WTRUoperating on multiple carriers) and/or resources. The resources maycomprise time/frequency/beam resources. Resource selection may compriseselection of a set of resources (e.g., which may be repeatedperiodically) within a resource pool. Resource selection may compriseselection of a resource pool or a resource pattern within a set ofpools/patterns.

A WTRU in a unicast link may be responsible for resource/carrierreselection. For example, one of two WTRUs may be denoted theresponsible WTRU for performing resource/carrier reselection. Theresponsible WTRU may be determined based on one or more of thefollowing.

The responsible WTRU may correspond to a WTRU configured to perform aspecific role in a link establishment procedure. For example, theresponsible WTRU may be the WTRU that initiates the link establishmentprocedure.

The responsible WTRU may correspond to a WTRU having the lowest orhighest value of an observed quality metric (e.g., with respect to aresource pool or a set of allowable resources) for unicast. For example,multiple WTRUs may periodically exchange measured CBR and theresponsible WTRU may be selected as the WTRU having the lowest orhighest CBR.

The responsible WTRU may correspond to a WTRU having the highest orlowest value of a configured or pre-configured parameter or identifier.For example, the WTRU with the highest or lowest L2 ID may be denoted asthe responsible WTRU.

The responsible WTRU may correspond to a WTRU having certain coveragecharacteristics with respect to the network and/or a synchronizationsource. In examples, a WTRU synchronized to a synchronization sourcethat is closest (e.g., in terms of synchronization levels) to the gNBmay be determined as the responsible WTRU. In examples, a WTRU havingbetter Uu RSRP at a given time may be denoted as the responsible WTRU.

A WTRU may perform carrier/resource reselection based on metricsassociated with resources used with a peer WTRU. A WTRU may performresource/carrier reselection based on certain triggers (e.g., which maybe related to QoS) related to a peer WTRU and/or triggers related to theresources used for communication with a peer WTRU. A WTRU may performresource/carrier reselection based on (e.g., as a result of) one or moreof the following.

A WTRU may perform resource/carrier reselection based on the receptionof an indication or request to perform carrier/resource reselection. AWTRU may transmit/receive a carrier/resource reselection request to/fromanother WTRU. For example, a WTRU may perform carrier/resourcereselection in response to reception of a request from another WTRU. AWTRU may transmit a carrier/resource reselection request to a peer WTRUin response to a change in CBR or a similar measurement of channeloccupancy by the WTRU. A WTRU may transmit a carrier/resourcereselection request to a peer WTRU based on a counter of how manyperiodic or non-periodic data/PDUs transmitted by the WTRU reach apre-configured value. A WTRU may transmit a carrier/resource reselectionrequest to a peer WTRU based on a change in a resource poolconfiguration at the WTRU. A WTRU may transmit a carrier/resourcereselection request to a peer WTRU based on the WTRU not being able totransmit feedback (e.g., HARQ or CSI) to a peer WTRU using currentlyconfigured carriers/resources (e.g., due to TX carrier limitation). AWTRU may transmit a carrier/resource reselection request to a peer WTRUin response to data arrival at the WTRU (e.g., the data may have anew/different QoS requirement). A WTRU may transmit a carrier/resourcereselection request to a peer WTRU based on any other suitable triggermentioned herein in association with a data rate.

A WTRU may perform resource/carrier reselection in response to receptionof quality information from a peer WTRU, e.g., relating to configuredresources and/or carriers for a peer WTRU. A WTRU may performcarrier/resource reselection based on quality information reported by apeer WTRU. A WTRU may transmit quality information such as qualityinformation associated with the resources/carriers configured for usagebetween the WTRU and a peer WTRU. Such quality information may includeCBR measurement(s) and/or a similar measurement of load on a set ofresources and/or carriers configured for usage between two WTRUs. Suchquality information may include RSRP/RSRQ/CQI/etc. of a known signaltransmitted by a peer WTRU. Such quality information may includemeasured RSSI of a resource and/or a set of resources on one or morecarriers. Such quality information may include HARQ metrics, such as thenumber of HARQ ACK/NACK per resource or set of resources associated witha carrier.

A WTRU may receive quality information from a peer WTRU and may performcarrier/resource reselection based on such quality information. Forexample, a WTRU may perform carrier/resource reselection if the CBRreported by a peer WTRU is below a threshold. A WTRU may performcarrier/resource reselection if the measured RSSI on a set of resourcesreported by a peer WTRU is below a threshold.

A WTRU may perform resource/carrier reselection based on its ownmeasurements of resource quality including the WTRU's own measuredquality metrics on a set of resources. Such quality metrics may includeCBR measurement(s) or a similar measurement of the load on a set ofresources. Such quality metrics may include RSRP/RSRQ/CQI/etc. of aknown signal transmitted by a peer WTRU. Such quality metrics mayinclude measured RSSI of a resource and/or set of resources on one ormore carriers. Such quality metrics may include HARQ metrics, such asthe number of HARQ ACK/NACK per resource or set of resources associatedwith a carrier.

A WTRU may perform resource/carrier reselection based on a combinationof quality information measured by the WTRU and reported by a peer WTRU.The WTRU may perform carrier/resource reselection based on its ownquality metrics and/or quality information reported by a peer WTRU. Forexample, a WTRU may determine a weighted average of certain qualitymetrics (e.g., CBR) between its own measured value(s) and value(s)reported by a peer WTRU and may perform resource reselection if thecombined average is below a configured threshold.

A WTRU may send an indication of performed carrier/resource reselectionto a peer WTRU. A WTRU may perform carrier/resource reselection, and maysend an indication of such selection/reselection to a peer WTRU. TheWTRU may send such indication, for example, if the carrier/resourcereselection may affect the resources/carriers utilized by the peer WTRU.For example, the WTRU may send the indication if the carrier/resourcereselection may affect the resources used by a peer to transmit HARQfeedback, or when common carriers are shared by the two WTRUs.

An indication of carrier/resource reselection may comprise one or moreof a set of new carriers/resources selected by a WTRU or a time instantin which the new carrier/resources may start to be used.

A WTRU may send an indication of carrier/resource reselection using oneor more of a SL MAC CE, a SL RRC message, or an indication on adedicated sidelink physical channel such as an SCI with a specific field(e.g., with the contents of the indication included in a PhysicalSidelink Shared Channel or PSSCH).

Logical channel prioritization or LCP may take into account thattransmissions can be sent to one or more destinations (e.g., one or moreWTRUs). For example, LCP may take data from multiple relateddestinations to satisfy a grant (e.g., a single grant). A WTRU may beconfigured with one or more (e.g., a group or a set of) destinations,for example, as an LCP restriction or part of an LCP restriction.

In examples, a WTRU may be configured with one or more (e.g., a group orset of) destination addresses such as L2 destination IDs. Thesedestination addresses may be considered common from the point of view ofLCP restrictions. In examples, a WTRU (e.g., a present WTRU) maymultiplex PDUs intended for different destination addresses (e.g.,different WTRUs connected to the present WTRU via a sidelink) oncondition that those destination addresses belong to a group or set(e.g., a configured group or set of destinations or WTRUs). In examples,a WTRU may be configured to not multiplex PDUs intended for destinationsthat are associated with different groups or sets in the sametransmission.

A WTRU may be configured with a group or set of destination addresses invarious ways including, for example, upper layer (e.g., RRC) signaling.For example, the WTRU may receive information (e.g., configuration) froman upper layer (e.g., a V2X layer, a non-access stratum or NAS layer, anRRC layer, etc.) regarding L2 destination addresses associated with agroup. The WTRU may derive information regarding one or more L2destination addresses associated with a group based on upper layersignaling (e.g., based on signaling at a V2X layer, a non-access stratumor NAS layer, an RRC layer, etc.).

A WTRU may receive a configuration for a group or set of destinationaddresses from a network. For example, the WTRU may receive an RRCmessage from the network with a list of destination addresses that maybe related (e.g., the destination addresses may form or belong to agroup).

A WTRU may be configured with a group or set of destination addressesimplicitly, e.g., based on L2 destination IDs (e.g., bit stringsidentifying different destination addresses or devices). For example,the WTRU may identify (e.g., determine) one or more WTRUs that may bepart of the same group based on a relationship among the L2 destinationIDs of such destinations (e.g., based on the destination addresseshaving a common set of MSBs or LSBs and/or based on some otherinspection of the L2 destination IDs). The WTRU may provide suchgrouping on condition that the L2 destination IDs are associated withunicast and/or groupcast. For example, groupcast destination IDs may begrouped and unicast destination IDs may be grouped. In examples, agroupcast ID may not be grouped with a unicast ID. In examples, agroupcast ID may be grouped with a unicast ID, for example where theunicast ID is associated with a destination that is also associated withthe groupcast ID.

In examples, a grant may service (e.g., may designated for) a singledestination and this may lead to starvation of lower-prioritydestinations. For example, this (e.g., resource starvation) may be thecase when a destination address having the highest priority data isselected (e.g., to use the grant) and/or when a grant is filled withdata associated only with that destination during logical channelprioritization. A WTRU may be configured to select a destination addressassociated with a grant based on the bucket size(s) (e.g., a bucket sizeparameter) associated with that destination, e.g., so that a destinationmay represent a single destination or a set of destinations inaccordance with one or more LCP restrictions associated with the set orgroup of destinations. In examples (e.g., when selecting a destinationaddress for a grant), a WTRU may select multiple destinations if suchdestinations are associated with a same group. In examples (e.g., whenselecting multiple destinations associated with a same group for a grantor when performing destination selection based on the priorities ofLCHs), a WTRU may consider multiple (e.g., all) LCHs that are associatedwith the destinations of a same group together and decide whether thedestination or group of destinations should be selected.

A WTRU may select the logical channel(s) to be serviced by a grant(e.g., at the start of an LCP procedure) by determining the prioritizedbit rate of one or more (e.g., all) logical channels associated with adestination. For example, a WTRU may select a destination address or aset of destination addresses, and the logical channel(s) associated withthe destination address or addresses may be processed based on ameasurement of the prioritized bit rate (PBR) and/or a bucket sizeparameter (e.g., such as the bucket size (Bj) associated with logicalchannel j) of the logical channel(s) associated with the destinationaddress or addresses.

A WTRU may be configured to consider a subset (e.g., only a subset) oflogical channels when evaluating the criteria to be used for destinationaddress selection. Such a subset of logical channels may be definedbased on a specific QoS requirement (e.g., minimum communication range,priority, latency, etc.). For example, the WTRU may be configured tosatisfy one or more criteria when selecting a destination address byconsidering only the logical channels associated with a specificpriority or a specific set of priorities. Such a priority or set ofpriorities can be provided, for instance, with a grant (e.g., for mode1), or the priority or set of priorities may be associated with aproperty of resource selection results (e.g., for mode 2).

In one or more (e.g., any) of the examples given herein, a WTRU may beconfigured to consider the logical channels that satisfy a certain LCPrestriction (e.g., in addition to other criteria specified herein). Forexample, a WTRU may be configured with an LCP restriction based on agrant type (e.g., a given logical channel may be allowed or disallowedto use grants of a specific type). In these cases, the WTRU may considerthe LCHs that are allowed to use a specific type of grants whenselecting a destination address (e.g., to use the specific type ofgrants) and the WTRU may not consider LCHs that are not allowed to usethe specific type of grant. For example, when a WTRU is configured toperform destination selection based on a combination of priority and/orPBR (e.g., as described herein), the WTRU may consider the LCHs that areallowed to use a specific type of grants.

A WTRU may select a destination address using one or more of thecriteria described herein. For example, a WTRU may select a destinationaddress associated with a logical channel having the highest priorityand/or having Bj>0. A WTRU may use one or more criteria when selecting adestination address. For example, a WTRU may use a first criteria toselect a destination address. If more than one destination addresssatisfies the first criteria and/or if multiple destination addressesshare a same parameter value associated with the first criteria, theWTRU may use a second criteria to select the destination address. Ifnone of the destination addresses satisfy the first criteria, the WTRUmay use a second criteria to select the destination address. These rulescan be extended (e.g., generalized) to any number of criteria. Forexample, if more than one destination address satisfies the (n)thcriteria, the WTRU may then consider the (n+1)th criteria. Similarly, ifthe (n)th criteria is not satisfied by any destination address, the WTRUmay then consider the (n+1)th criteria.

A WTRU may select a destination address for which Bj (e.g., the bucketsize associated with a logical channel with pending data) has thelargest non-zero value. If multiple destination addresses are associatedwith a logical channel having the same Bj value, the WTRU may select thedestination address having the highest priority. If multiple destinationaddresses are associated with respective logical channels (e.g., logicalchannels with pending data) that have the same Bj value and the samepriority, the WTRU may select a destination address (e.g., among themultiple logical channels) such that satisfying the grant with (e.g.,using the grant for) the logical channel(s) associated with thatdestination address will minimize the total amount of data selected fortransmission that exceeds the Bj for the logical channel associated withthe selected destination address. For example, when multiple destinationaddresses are associated with respective logical channels that have thesame Bj value and the same priority, the WTRU may select a destinationaddress that results in the minimum amount of the grant being used fordata transmission that exceeds Bj (e.g., the sum of the data transmittedon each logical channel j that exceeds Bj is minimized).

FIG. 2 illustrates how a WTRU may determine a destination for which aset of sidelink resources (e.g., a grant in Mode 1 or a set ofautonomously selected resources in Mode 2) may be used. As shown, theWTRU may have six logical channels, LCH1-LCH6, with available data totransmit. The data associated with each logical channel may includeprioritized data (e.g., data that, if transmitted, would satisfy the Bjassociated with the logical channel) and/or non-prioritized data (e.g.,data that, if transmitted, would exceed the Bj associated with thelogical channel) and each of the logical channels may be associated witha destination. For example, LCH1 and LCH2 may be associated withdestination D1 and may have both prioritized data and non-prioritizeddata. LCH3 and LCH4 may be associated with destination D2 and may haveonly non-prioritized data. LCH5 and LCH6 may be associated withdestination D3 and may have both prioritized data and non-prioritizeddata. In an example situation, the six logical channels may have equalpriority, and the WTRU may, in response to determining that the set ofsidelink resources have become available, select D1 as the destinationfor transmission since the transmission to D1 may result in the leastamount of grant being used for non-prioritized data (e.g., as comparedto the transmission to D2 or D3).

For one or more of the criteria (for determining a destination address)described herein, a WTRU may consider the amount of data it canmultiplex from one or more logical channels associated with adestination based on the subset of logical channels that satisfy aspecific QoS restriction. For example, when evaluating a criterion thatis based on the amount of data multiplexed into a grant for a specificlogical channel, the WTRU may consider that only the data restricted bythe QoS requirement can be multiplexed into the grant.

A WTRU may select a destination address having the largest or smallestvalue of a QoS parameter. For example, a WTRU may select a destinationaddress that has pending data and that is associated with a logicalchannel having the largest or smallest value of a QoS-related parameter.For example, the WTRU may select a destination address associated with alogical channel having the highest priority among a set of logicalchannels (e.g., among all logical channels) with pending data. Forexample, the WTRU may select a destination address that is associatedwith a logical channel having the smallest latency budget. The QoSparameter used for the decision may be configured by an upper layer(e.g., a network or NAS layer). Other QoS parameters includingreliability and minimum communication range may also be used for thispurpose.

A WTRU may select (e.g., only select) one or more destinations having abucket size (e.g., Bj) greater than a threshold (e.g., greater than 0).In examples, a WTRU may select a destination address that has at leastone logical channel with pending data and with Bj>0. A WTRU may select adestination address associated with the highest priority logicalchannel. For example, A WTRU may select a destination address associatedwith the highest priority logical channel in the case of multipledestinations having logical channel(s) with Bj>0.

A WTRU may select one or more destinations having the largest bucketsize (e.g., as represented by Bj) for a logical channel. In examples, aWTRU may select a destination address associated with a logical channelthat has pending data and the largest bucket size (e.g., as representedby Bj) such that the bucket size is greater than a threshold (e.g.,greater than 0). In examples (e.g., in the case of multiple destinationshaving logical channel(s) with the same bucket size), a WTRU may selectthe destination with the highest priority logical channel for a givengrant.

A WTRU may select one or more destinations that have the largest totalbucket size (e.g., as represented by the sum of Bjs) for all or a subsetof the logical channels associated with each of the destination(s). Inexamples, a WTRU may select the destination address having the largesttotal bucket size (e.g., total bucket size of all logical channelsassociated with that destination). In examples, a WTRU may select thedestination address having the largest total bucket size among alllogical channels (e.g., logical channels with pending data) having Bj>0.In examples (e.g., in the case of multiple destinations having the sametotal bucket size), a WTRU may select the destination with the highestpriority logical channel. In examples, a WTRU may select the destinationaddress having the largest total bucket size of the logical channelsthat share a specific parameter value (e.g., having the same priority).For instance, a WTRU may select the destination address that has thelargest total Bj associated with a specific priority. The specificpriority may correspond to the priority of the highest priority LCHhaving data available from a certain destination (e.g., among multipledestinations).

A WTRU may select a destination so that the amount of resource wasteassociated with a grant may be reduced or minimized. For example, theWTRU may select a destination so that the difference between the size ofa grant and the actual buffer size of one or more (e.g., all) logicalchannels associated with that destination may be reduced or minimized(e.g., in the case where a grant is larger than the total buffer sizefor the logical channels associated with that destination). In examples(e.g., when there is at least one destination for which the total buffersize is larger than a grant), a WTRU may select any of thosedestinations.

A WTRU may compare the total buffer size of logical channels associatedwith each destination and select the destination that has the largesttotal buffer size.

A WTRU may select a destination that is associated with the highestpriority logical channel and that has a bucket size greater than acertain threshold (e.g., with Bj>0). In examples, a WTRU may select thedestination address having the highest priority logical channel whereBj>0. The WTRU may, in response to determining that a set of resourcesare available for the WTRU to perform a transmission, identify one ormore logical channels with respective bucket size parameters (e.g., Bj)having a value greater than zero. The WTRU may further identify, fromthe one or more logical channels, a logical channel that has the highesttransmission priority. The WTRU may then select a destination associatedwith the highest priority logical channel as the destination of thetransmission (e.g., as the destination to use the grant). In examples(e.g., in the case of multiple destination addresses being associatedwith logical channel(s) that have Bj>0 and that have the same priority),a WTRU may select the destination based on one or more of the following.

In examples where multiple destination addresses are associated withlogical channel(s) that have Bj>0 and that have the same priority, theWTRU may select the destination in response to determining that thedestination is associated with a logical channel with Bj>0, where thatspecific logical channel has the largest value of Bj among the multipledestination addresses (e.g., among the logical channels associated withthe multiple destination addresses).

In examples where multiple destination addresses are associated withlogical channel(s) that have Bj>0 and that have the same priority, theWTRU may select the destination in response to determining that thedestination has the largest value of total bucket size (e.g., the totalbucket size may correspond to a sum of the bucket sizes of all logicalchannels associated with a destination).

In examples where multiple destination addresses are associated withlogical channel(s) that have Bj>0 and that have the same priority, theWTRU may select the destination based on any other of conditionsdescribed herein in association with the selection of a destinationaddress (e.g., based on a previous selection, based on PRB, based onbucket size, based on the destination for which the grant can satisfythe largest number of logical channels with Bj>0, etc.).

A WTRU may select a destination based on previous selections. Doing somay ensure that destinations associated with logical channel(s) havingBj>0 be selected fairly. For example, a WTRU may determine a set ofdestination addresses associated with a logical channel having Bj>0 andmay select one or more destinations sequentially (e.g., in a round robinmanner) among different initiations of a LCP procedure at grantreception. The sequential selection of destination addresses (e.g., withlogical channels having Bj>0) may be weighted to prioritize certaindestinations based on one or more of the following.

The weighting may be based on the priority of the logical channel(s)having Bj>0. In examples, destinations with the highest priority logicalchannels may be serviced first in the sequence of destination addresses.In examples, destinations with the highest priority logical channels maybe serviced more often in the sequence of destination addresses.

The weighting may be based on the value of Bj for the logical channel(s)associated with a destination. For example, destinations with thelargest Bj or largest total Bj may be serviced first or more often inthe sequence of destination addresses.

The weighting may be based on the value of prioritized bit rate (PBR) ortotal PBR for a destination. For example, destinations with the highestvalue of PBR for a particular logical channel or the highest value oftotal PBR (e.g., the sum of PBRs) across multiple (e.g., all) logicalchannels may be serviced first in the sequence or may be services moreoften in the sequence.

A WTRU may select a destination based on PBR. For example, a WTRU mayselect a destination address having the highest PBR of a specificlogical channel or the highest total (e.g., sum of) PBR across multiple(e.g., all) logical channels. A WTRU may use such selection criteriaunder certain conditions (e.g., in the case where two destinations areboth associated with logical channel(s) having Bj>0 and/or where twodestinations are both associated with logical channel(s) having thehighest priority among multiple destinations).

A WTRU may select a destination for which a grant can satisfy thelargest number of logical channels (e.g., logical channels with Bj>0).In examples, a WTRU may select a destination address such that a pendinggrant, when applied to the logical channels associated with thatdestination, can satisfy the largest number or percentage of logicalchannels (e.g., logical channels associated with the destination) thathave Bj>0 and/or that have a specific priority. For example, adestination address may be selected such that it satisfies the largestnumber of logical channels having Bj>0 and/or having a priority greaterthan a specific threshold. For example, a destination address may beselected such that it satisfies the largest number or percentage oflogical channels associated with the destination that have Bj>0, wherethe number or percentage of logical channels are associated with thehighest priority among those logical channels whose Bj is greater than0. For example, a destination having more than one logical channel withBj>0 may be selected for a specific grant if the grant can satisfy alllogical channels with Bj>0 when the grant is used.

A WTRU may select a destination having the largest weighted Bj (e.g.,bucket size). The WTRU may apply a weight (k) to the value of Bjassociated with one or more logical channels (e.g., with each logicalchannel) and may select the destination address associated with alogical channel with pending data and having the largest value of k*Bj>0among all logical channels. The WTRU may select the destination addresshaving the largest total value of k*Bj across all logical channels thathave pending data and that are associated with the destination. The WTRUmay select the destination address having the largest total value ofk*Bj across all logical channels that are associated with thedestination and that have Bj>0.

A WTRU may be configured with a weight (k) to be applied to one or moreof the logical channels described herein. The WTRU may determine theweight based on one or more of the following.

The WTRU may determine the weight based on the priority or any relatedQoS parameter of a logical channel. For example, the WTRU may apply aconfigured weight for a given priority, latency, reliability, minimumcommunication range, and/or other characteristics of the logicalchannel.

The WTRU may determine the weight based on the PRB configured for alogical channel. For example, the WRU may determine the weight from thePBR based on a mapping of PBR to weight (k).

The WTRU may determine the weight based on the cast type (unicast,groupcast, broadcast, etc.) associated with the destination. Forexample, the WTRU may apply a different weight (e.g., configured weight)for one or more cast types (or each cast type).

A WRU may minimize the amount of data transmitted in the grant thatexceeds Bj (e.g., minimizing grant usage for non-prioritized data).

A WTRU may select a destination so as to minimize the total amount ofdata in a grant (e.g., total amount of data transmitted using the grant)that exceeds the respective Bj's of one or more logical channelsassociated with the destination. For example, the WTRU may, uponselecting a destination, select logical channels to be multiplexed intoa grant based on one or more Uu LCP rules (e.g., currently determined orpreconfigured LCP rules). Such rules may include, for example,satisfying Bj>0 first, and then filling a grant with pending data fromone or more logical channels that exceeds the Bj's of these logicalchannels (e.g., if the grant allows these actions). The WTRU may selecta destination so as to minimize the total amount of data (e.g., dataexceeding the non-zero Bj's of one or more logical channels) multiplexedonto a grant (e.g., when the grant is larger than zero). The WTRU mayselect a destination such that a grant is used predominantly to satisfythe pending data of one more logical channels that is associated with acurrent bucket size (e.g., such a current bucket size may bepreconfigured).

A WTRU may select a destination that satisfies all or a percentage(e.g., a majority) of configured bucket sizes. For example, the WTRU mayselect a destination such that a received grant can accommodate all or amaximum amount of the data of logical channels having Bj>0. The WTRU mayselect a destination such that the respective Bj's of all or apercentage of the logical channels with pending data are equal to orless than zero (e.g., Bj<=0) following the performance of a LCP. TheWTRU may select a destination for which a grant may accommodate thelargest portion of data associated with the bucket sizes of logicalchannels having pending data. In examples, the WTRU may select adestination such that the total Bj of logical channels with pending datafollowing a LCP and for which Bj is still >0 is minimized. In examples,the WTRU may select a destination such that the total Bj of logicalchannels with pending data following a LCP and for which Bj is still >0minimizes the ratio of total Bj to grant size.

A WTRU may select a destination that satisfies a certain percentage(e.g., a majority) of logical channels with pending data. For example, aWTRU may select a destination for which a grant can accommodate amajority (e.g., most) of the pending data of logical channels associatedwith the destination. The WTRU may select a destination for which all ora majority of the logical channels may have no remaining data followingthe performance of a LCP. For example, the WTRU may select a destinationfor which the remaining data on any logical channel associated with thatdestination is minimized.

A WTRU may select a destination such that the bucket size of one or morelogical channels associated with that destination or the total bucketsize of all logical channels associated with that destination (e.g.,logical channels having pending data) is above a certain threshold. Forexample, the WTRU may be allowed to select a destination if the total Bjamong all logical channels associated with that destination and/orhaving pending data is above a preconfigured threshold.

A WTRU may select a destination based on a bucket size (or an equivalentmetric) associated with the destination address. For example, the WTRUmay maintain a variable, Bd, corresponding to the bucket size (e.g.,total bucket size of all logical channels) associated with a (e.g.,each) destination address. The WTRU may initialize Bd (e.g., to have avalue of zero) when a logical channel associated with destination d isinitiated. The WTRU may increment Bd by a destination-based PBR*T, whereT may represent the time since the last LCP procedure. The WTRU mayselect the destination address with the largest Bd>0. The WTRU mayselect the destination address having the highest priority logicalchannel with pending data and having Bd>0. The WTRU may determine thevalue of PBR for a specific destination as a function of the configuredPBR of one or more (e.g., each) logical channels associated with thedestination. The WTRU may be configured with a value of PBR to use for a(e.g., each) destination address.

A WTRU may be restricted from selecting a same destination addresssuccessively. The WTRU may select a destination address using one ormore of the criteria discussed herein. The WTRU may be configured with arestriction regarding how often or frequently the WTRU may select thatsame destination address in subsequent (e.g., successive) LCPprocedures. Such a restriction may be conditioned on or applied in thescenario where the WTRU is selecting a destination address from multipledestination addresses having Bj>0 or where there are multipledestination addresses that satisfy at least one of the criteriadescribed herein. For example, following the selection of a destinationaddress for a LCP, the WTRU may exclude the selection of the samedestination address for the next N LCP procedures and/or grants if thereis another destination address satisfying one or more the criteriadescribed herein. The value of N may be configurable and may furtherdepend on one or more of the number of destination addresses configuredfor transmission by the WTRU, the number of destination addressesassociated with a logical channel having Bj>0 at a given time, or thenumber of destination addresses having one or more logical channels withPDB larger than a threshold.

In examples, a WTRU may, following the selection of a destinationaddress for a LCP, exclude the selection of the same destination for LCPfor a certain period of time. The duration of the time period may dependon similar conditions or factors as described above. The exclusion maybe applied, for example, if there are one or more other destinationaddresses that also satisfy the criteria discussed herein (e.g. havingBj>0, etc.)

A WTRU may use a timer for (e.g., associate a timer with) a destinationaddress. The timer may be, for example, a destination starvationavoidance timer. The timer may reflect the amount of time passed sincethe destination was last selected for a LCP procedure. For example, aWTRU may start a timer for a destination address upon reception of dataon a logical channel (e.g., a logical channel having Bj>0) associatedwith the destination address. The WTRU may select the destinationaddress (e.g., select the destination address again) when the timerassociated with that destination address expires.

A WTRU may determine which decision criteria to use or the order inwhich these criteria should be used for destination address selectionbased on channel conditions. For example, one measure of such channelconditions may be the channel busy ratio of a sidelink (SL). A WTRU mayselect a destination address based on priority (e.g., based on thedestination having the highest priority logical channel) when thechannel busy ratio of a SL is above a threshold. The WTRU may select adestination based on a logical channel having the largest Bj>0 when thechannel busy ratio is below a threshold. The WTRU may use one or moreother criteria discussed herein for destination selection based onchannel conditions.

A WTRU may determine which decision criteria to use or the order inwhich these criteria should be used for destination address selectionbased on which decision criteria are more critical at the time of a LCP.Such criticality may be determined based on the associated value of aparameter used for the selection. For example, the WTRU may use one ormore criteria associated with a total Bj (e.g., with a value greaterthan zero) for destination selection when a measured value of the totalBj for a destination is larger than a certain threshold. The WTRU mayuse one or more criteria associated with the largest Bj (e.g., with avalue greater than zero) for a single logical channel when a measuredvalue of the total Bj for a destination is equal to or smaller than thethreshold. For example, the WTRU may use the priority of a logicalchannel as criteria for determining a destination address if at leastone logical channel has data pending with a priority above a certainthreshold, and the WTRU may use another criteria for determining adestination address if no logical channel has pending data with apriority above the threshold. A WTRU may use one or more other criteriadiscussed herein for destination selection based on the criticality ofthe criteria.

A WTRU may be configured with one or more destination addresses thatshould be given a higher priority or weight when being considered fordestination selection under any of the decision criteria discussedherein. For example, the WTRU may be configured to apply an offset toone or more decision criteria values (e.g., Bj, priority, etc.) whencomparing different destination addresses using the decision criterial.To illustrate, the WTRU may be configured to select one destination overanother when the two destinations both satisfy a specific criteria orboth have the same value of a specific metric (e.g., Bj, priority,etc.). In examples, the destinations given higher priority may be thoseassociated with a specific cast. For example, a WTRU may prioritizedestination addresses associated with unicast over those associated withgroupcast or broadcast.

A WTRU may use a combination of criteria for destination selection.

In examples, a WTRU may select a destination address that has thehighest priority logical channel with data available in the WTRU'sbuffers and for which the current value of Bj is >0. In examples (e.g.,if there are no LCHs having Bj>0), a WTRU may select the destinationaddress that has the highest priority LCH. In examples (e.g., if thereare multiple destination addresses with Bj>0 and where the highestpriority LCH is the same for the multiple destination addresses), a WTRUmay select the destination that may minimize the amount data (e.g., datatransmitted using a grant) exceeding Bj, or the WTRU may select thedestination for which the total Bj is the largest (e.g., for the highestpriority), as described herein.

In examples, a WTRU may select the destination having the highestpriority LCH. If multiple destinations have the same highest priorityLCH, the WTRU may select the destination with the largest value of Bjassociated with that destination address. These selection techniques maybe used in conjunction with the other techniques described herein (e.g.,for the case when there are no LCHs having Bj>0).

A WTRU may perform one or more of the following operations afterdestination selection. The WTRU may perform an NR Uu-based LCP procedureacross the logical channels associated with the selected destination.For example, the WTRU may attempt to satisfy the logical channels havingBj>0 in a decreasing priority order. A WTRU that selects a destinationgroup, as described herein, may perform such an LCP procedure across oneor more (e.g., all) logical channels of the destinations that areassociated with the destination group. For example, the WTRU may satisfythe logical channels with Bj>0 in one or more (e.g., all) destinationsassociated with the selected logical channel group in a decreasingpriority order (e.g., across all logical channels in the selecteddestination group).

A WTRU may be configured to adjust one or more parameters or behaviorssuch as those associated with starvation avoidance based on a congestioncondition. For example, the WTRU may adjust parameters and/or behaviorsrelated to LCP based on a measured congestion condition of a sidelink(e.g., using a channel busy ratio or CBR). Starvation avoidance mayrefer to rules, operating parameters, behaviors, efforts, etc. appliedby a network and/or a WTRU so that the WTRU may avoid or mitigateshortage of resources for sending or receiving a transmission.

A WTRU may be configured to change and/or alternate configured values ofone or more of the following parameters based on the presence ofcongestion and/or the level of congestion associated with sidelinkresources. These parameters may include, for example, the prioritizedbit rate (PBR) for one or more logical channels, the bucket sizeduration (BSD) for one or more logical channels, and/or a bucket sizeparameter (e.g., Bj and/or a similar bucket size parameter).

A WTRU may be configured with different values of PBR for a givenlogical channel (e.g., depending on a measured congestion level). Forexample, the WTRU may be configured to apply a first PBR for a logicalchannel when the measured CBR meets a first criteria (e.g., when themeasured CBR is within a first configured range of CBRs), and may applya second PBR for a logical channel when the measured CBR meets a secondcriteria (e.g., when the measured CBR is within a second configuredrange of CBRs).

A WTRU may be configured to operate in one or more of the following ways(e.g., to modify one or more LCP related behaviors) based on acongestion condition. The WTRU may decide whether to select an amount ofdata based on Bj in accordance with a CBR. The WTRU may decide toperform or skip starvation avoidance during LCP depending on a measuredcongestion condition. For example, if the measured congestion conditionmeets a first criteria (e.g., a measured congestion level is within afirst configured range of CBRs), the WTRU may perform LCP by selectingan amount of data from a selected logical channel up to the value of Bj.If the measured congestion condition meets a second criteria (e.g., ameasured congestion level is within a second configured range of CBRs),the WTRU may perform LCP by selecting available data (e.g., all theavailable data if there is enough space in a corresponding grant) for aselected logical channel. The WTRU may determine whether or not toselect an amount of data based on Bj in accordance with the specificlogical channel involved. For example, the WTRU may be configured withseparate ranges of CBRs within which the WTRU may perform starvationavoidance (e.g., selecting data based on Bj) or not perform starvationavoidance (e.g., selecting data up to the entire amount of dataavailable for a logical channel). Based on the configuration, the WTRUmay (e.g., for a specific instance of LCP and/or a specific measuredCBR) decide to select data based on Bj for a first logical channel andnot select data based on Bj for a second logical channel.

A WTRU may decide whether to consider Bj in destination addressselection based on a CBR. A WTRU may start/stop consideration of Bj,e.g., for a subset of logical channels, during destination addressselection depending on a measured congestion level. For example, inconditions of high congestion (e.g., above a certain threshold), theWTRU may perform LCP by selecting a destination with the highestpriority. In conditions of low congestion, the WTRU may perform LCP byselecting a destination with the highest priority and Bj>0. The WTRU mayperform LCP by selecting a destination with the highest priority andBj>0 under similar conditions for starvation avoidance, as discussedherein. The WTRU may consider whether Bj is greater than 0 for somelogical channels, and my not consider whether Bj is greater than 0 forother logical channels. The WTRU may determine whether or not toconsider Bj>0 base on the level of congestion. For example, the WTRU maybe configured with a per logical channel congestion threshold fordetermining whether and/or when to start/stop consideration of Bj>0during destination address selection.

A WTRU may decide whether to increase Bj depending on a measuredcongestion condition. A WTRU may start, stop, or pause bucket size(e.g., Bj) calculation and/or accumulation depending on a measuredcongestion condition. For example, the WTRU may freeze the value of Bj(e.g., not calculating and/or accumulating Bj value) when congestionincreases (e.g., when a congestion level moves from below a configuredthreshold to above the configured threshold, or from one configuredrange to another range). The WTRU may continue Bj calculation whencongestion decreases.

A WTRU may compute Bj differently depending on congestion conditions. AWTRU may compute its bucket size (e.g., Bj) differently depending on ameasured congestion condition. For example, the WTRU may be configuredwith an offset and/or a multiplication factor that the WTRU may apply inthe calculation of Bj, for example, when a measured congestion levelsatisfies certain rules and/or conditions (e.g., when the congestionlevel is within a configured range of CBRs).

A WTRU may select an amount of data as a function of Bj. Such a functionmay depend on a measured congestion condition. A WTRU may continue toapply starvation avoidance and/or computation of Bj according to a PBR.The WTRU may consider a modified value of Bj that may depend oncongestion conditions. For example, the WTRU may consider (e.g., onlyconsider) data up to a certain percentage of Bj, where such percentagemay depend on (e.g., may vary based on) a congestion level and/or aspecific logical channel. For example, the WTRU may be configured (e.g.,for each logical channel) with a percentage of Bj for selecting anamount of data, where the percentage may depend on a measured CBR.

A WTRU may be configured to determine and/or change SLRB configuration(e.g., such as a RLC mode) based on a CBR.

A WTRU may be configured with a CBR-dependent configuration thatcorresponds to a QoS flow or QoS profile. The WTRU may change a SLRBconfiguration based on a measured CBR. For example, the WTRU may beprovided with a different configuration of some or all parametersassociated with a SLRB for a (e.g., each) range of measured CBR. TheWTRU may change a SLRB configuration when a measured CBR changes fromone range to another.

A WTRU may be configured with different values of one or more of thefollowing parameters, e.g., based on a measured CBR. For example, theWTRU may be configured to operate in a different RLC mode based on ameasured CBR (e.g., high CBR corresponds to an RLC unacknowledged mode(UM), low CBR corresponds to an RLC acknowledged mode (AM), etc.) TheWTRU may be configured to determine and/or use a polling retransmissiontimer value (e.g., T-pollRetransmit timer value) based on a measuredCBR. The WTRU may be configured to determine and/or use a maximumretransmission threshold (e.g., MaxRetxThreshold) based on a measuredCBR. The WTRU may be configured to determine and/or use a prohibit timervalue (e.g., T-statusProhibit timer value) based on a measured CBR. TheWTRU may be configured to determine and/or apply a LCH priority based ona measured CBR. The WTRU may be configured to determine and/or apply aConfiguredGrantTypelAllowed value based on a measured CBR. The WTRU maybe configured to determine and/or apply a PDCP discard timer value basedon a measured CBR. The WTRU may be configured to determine and/or applya PDCP T-reordering timer value based on a measured CBR.

A WTRU may select a resource pool during a mobility event (e.g., such asduring handover). A WTRU may determine the condition(s) for using anexceptional resource pool. When used herein, the term exceptionalresource pool may refer to a certain resource pool that is utilized whencertain conditions (e.g., atypical or exceptional conditions) aresatisfied. For example, a WTRU may determine whether to move Mode 1transmissions (e.g., transmissions associated with LCHs in Mode 1)during exceptional cases (e.g., during RLF, beam failures, mobilityevents, etc.) to an exceptional resource pool (e.g., use Mode 2transmissions on the exceptional resource pool) based on one or more ofthe following conditions.

A WTRU may determine whether or not to use an exceptional resource poolbased on the QoS of data in the WTRU's buffers that is associated withMode 1 transmission. For example, a WTRU may use an exceptional resourcepool for transmissions associated with a subset of logical channels. Thesubset of logical channels may be determined based on the configurationof parameters associated with those logical channels (e.g., whether theuse of an exceptional pool is allowed for the logical channels). Thesubset of logical channels may be determined based on the QoS associatedwith those logical channels (e.g., PQI/PFI, MCR, GBR, etc.)

A WTRU may determine whether or not to use an exceptional resource poolbased on the presence or configuration of resources for Mode 2transmission. For example, a WTRU may use an exceptional resource poolfor transmissions associated with Mode 1 if the WTRU is not configuredwith a resource pool for Mode 2 transmissions and/or if the WTRU is notallowed to perform Mode 2 transmissions. A WTRU may use an exceptionalresource pool for transmissions associated with Mode 1 if one or moreMode 2 resource pools are configured for transmissions that satisfy theQoS of one or more corresponding LCHs (e.g., if the LCHs are notrestricted to using Mode 2 resource pools).

A WTRU may determine whether or not to use an exceptional resource poolbased on the type of beam failure recovery (BFR) initiated (e.g., basedon whether the BFR is contention-based or contention free). For example,a WTRU may be configured to use an exceptional resource pool fortransmissions associated with Mode 1 when a beam failure occurs and beamfailure recovery is a contention-based.

A WTRU may determine whether or not to use an exceptional resource poolbased on the amount of time expired since beam failure recovery wastriggered. For example, a WTRU may be configured to use an exceptionalresource pool for transmissions associated with Mode 1 when a beamfailure recovery timer reaches a certain time following a number of beamfailure recovery attempts.

A WTRU may determine whether or not to use an exceptional resource poolbased on the congestion level (e.g., as indicated by CBR) of anexceptional resource pool. For example, a WTRU may be configured to usean exceptional resource pool for transmissions associated with Mode 1when the CBR of that exceptional resource pool is below a certainthreshold.

The conditions described above for selecting and/or using an exceptionalresource pool can be combined (e.g., selection/use of an exceptionalresource pool may be based on a combination of conditions). For example,the condition for using an exceptional resource pool in one option maydepend on parameters associated with another option. For example, a WTRUmay use an exceptional resource pool when contention-based BFR istriggered (e.g., a first condition) and the LCHs associated with Mode 1transmissions are part of a subset of logical channels allowed to usedsuch a pool (e.g., a second condition). The LCHs associated with Mode 1transmission that are part of the subset of channels to use such a poolmay be determined based on QoS of the LCHs. A WTRU may use anexceptional resource pool after a specific amount of time has passedsince BFR was triggered, where the specific amount of time may depend onthe LCHs configured or the LCHs that have data available in the WTRU'sbuffers.

Resource/carrier selection/reselection may be performed by a WTRUdespite the WTRU having limited TX capability.

A WTRU may support a minimum communication range. A WTRU may be allowedto transmit data in accordance with a minimum communication range (e.g.,a minimum required communication range) specific to the data. Theexamples are described herein in the context of sidelink, but maygenerally be applicable to any other scenario where a minimumcommunication range (MCR) requirement exists.

A WTRU may select at least one parameter for transmission of data over asidelink channel (e.g., PSSCH). The at least one parameter may include afrequency allocation, a time allocation, a modulation and coding scheme,a rank, a number of repetitions (or a maximum thereof), HARQinformation, and/or the like. The at least one parameter may include atransmission power level, a transmit antenna gain, and/or an effectiveisotropic radiated power (EIRP). At least one of the above parametersmay be configured or directly indicated by downlink control information(e.g., in network scheduled mode, e.g., Mode 1). For at least one of theabove parameters, the WTRU may be configured to select from a pluralityof candidate values or candidate combinations of values (e.g., in caseof more than one parameter). A subset of possible values may beconfigured as a range or as an explicit list.

A minimum communication range level may be mapped to a minimumcommunication range (e.g., a minimum required communication range). AWTRU may have data available for transmission. From the MAC sub-layerperspective, such data may comprise a set of MAC SDUs from at least onelogical channel. Higher layers may configure or provide a minimumcommunication range (e.g., a minimum required communication range) forone or more logical channels (e.g., for each logical channel) and/or forone or more MAC SDU (e.g., for each individual MAC SDU). A minimumcommunication range (e.g., a minimum required communication range) value(e.g., which may be expressed in meters) may be mapped to one of afinite set of minimum communication range levels, for example, accordingto a pre-defined or configured rule or formula. Each such minimumcommunication range level may be represented by an index and may beassociated with a path loss value (e.g., in dB units) pre-defined orconfigured by higher layers. Such path loss value may represent a pathloss to a device that is not expected to be exceeded (e.g., with a highprobability such as a 99% probability of not being exceeded) when thedevice is at a distance corresponding to the minimum communicationrange, e.g., based on an applicable propagation models.

As referred to herein, the acronym MCR may refer to a minimumcommunication range level or directly to a minimum communication range(e.g., a minimum required communication range), unless otherwisespecified. As referred to herein, a minimum communication range maycorrespond to a specific minimum communication range associated with atransmission. A minimum communication range may be tied to a logicalchannel. A minimum communication range may refer to a range of valuesfor a minimum communication range. For example, a network may configurea logical channel in a WTRU with a set of minimum communication rangevalues. Such a set of values may be a continuous set of minimumcommunication range values from a lower bound minimum communicationrange to an upper bound minimum communication range. When referred toherein, a minimum communication range may correspond to a specific valueof minimum communication range or a configured set of minimumcommunication range values associated with a transmission, a logicalchannel, a SLRB, and/or the like.

Different transmissions may be suitable for different minimumcommunication ranges. Logical channel prioritization (LCP) may beperformed according to one or more LCH restrictions based on thesuitability of a transmission to a minimum communication range.

A WTRU may determine, for a given transmission (e.g., a PSSCHtransmission), the suitability of the transmission for one or moreminimum communication ranges (e.g., for each minimum communicationrange). When performing logical channel prioritization, a WTRU maymultiplex data or select a logical channel associated with a minimumcommunication range for which the transmission is determined to besuitable.

The suitability of a transmission to a minimum communication range maybe determined according to one or more of the following. Suitability maybe obtained from downlink control information (e.g., in networkscheduled mode, e.g., Mode 1), e.g., along with other grant parameters.For example, a WTRU may receive the highest minimum communication rangefor which the grant is suitable via downlink control information. Theinformation may be provided explicitly in a field of DCI or implicitly(e.g., from the search space in which the PDCCH is decoded or from anRNTI value).

Suitability may be calculated based on one or more grant parametersand/or associated power parameters. For example, a WTRU may calculate amaximum achievable path loss based on a transmit power level, antennagain, and/or other parameters used in an existing power control formulasuch as the bandwidth (e.g., a number of resource blocks), the number ofcode blocks, and so on. Additional parameters may be configured for thispurpose. In examples, the maximum achievable path loss may be obtainedand a WTRU may determine that a grant is suitable for a minimumcommunication range if the maximum achievable path loss is higher thanthe path loss value associated to this minimum communication range. Inexamples, a WTRU may calculate (e.g., directly calculate) an expectedmaximum distance from a formula. The WTRU may determine that atransmission is suitable if the expected maximum distance is above theminimum communication range (e.g., the minimum required communicationrange).

A WTRU may be configured to select a combination of grant parametersfrom a table. One or more elements (e.g., each element) of the table maybe configured with a minimum value of transmission power or an effectiveisotropic transmission power for a (e.g., each) MCR. A WTRU maydetermine that a transmission using a combination of grant parameters asper an entry of the table is suitable for a minimum communication rangeif the transmission uses a transmission power (e.g., an effectiveisotropic transmission power) above a corresponding configured minimumvalue.

A maximum communication range may be defined/utilized. Such a maximumcommunication range may be defined in place of or in addition to theminimum communication range described herein. The examples describedherein in the context of a minimum communication range may be similarlyapplied to a maximum communication range. For example, where thesuitability is determined by calculation, a grant may be deemed suitableif a maximum achievable path loss is lower than the path losscorresponding to a maximum communication range level.

A WTRU may restrict or prioritize transmissions associated with aminimum communication range (e.g., MCR) that falls within thecommunication range of a selected LCH (e.g., a first selected LCH). Forexample, the WTRU may restrict or prioritize the multiplexing of SDUsassociated with similar minimum communication ranges when performing aLCP. The set of minimum communication ranges to be multiplexed may berelative to the minimum communication range of the first logical channelselected for transmission. The WTRU may select the first logical channelbased on one or more of the criteria discussed herein (e.g., priority,Bj>0, etc.). Following the selection of the first logical channel, theWTRU may be restricted to selecting or may prioritize the selection oflogical channels that have similar minimum communication ranges as thefirst logical channel. For example, the WTRU may be configured with aset of minimum communication ranges (e.g., for each LCH) and may select(e.g., only select) logical channels whose minimum communication rangeor minimum communication ranges fall within the configured set ofminimum communication ranges while using other criteria (e.g., such aspriority) for destination selection. The following examples illustratehow a WTRU may determine whether a LCH is within the range of anotherLCH.

A WTRU may be configured with a set of minimum communication rangevalues (e.g., for each logical channel), where the set of minimumcommunication range values may comprise a lower bound minimumcommunication range and an upper bound minimum communication range. Theminimum communication range may correspond to a range of distances thatinclude the minimum communication range requirements (e.g., specificminimum communication ranges) of one or more (e.g., all) QoS flowsmapped to a corresponding SLRB. For example, the WTRU may be configuredwith a minimum communication range [A B], where [A B]=[50m 500m]. TheWTRU may multiplex QoS flows with minimum communication rangerequirements that fall within the configured range (e.g., a minimumcommunication range requirement of 100m would fall within the configuredrange of [50m 500]) for a SLRB. A LCH may include QoS flows with minimumcommunication range requirements that fall within the range configuredfor the LCH. Once a first logical channel is selected, the WTRU maydetermine that a second logical channel is within the minimumcommunication range or minimum communication ranges of the first logicalchannel based on one or more of the following.

The WTRU may determine whether the minimum communication range of asecond logical channel overlaps with the minimum communication range ofa first logical channel. For example, if LCH1 is configured with aminimum communication range of [A,B] and LCH2 is configured with aminimum communication range of [C,D], then LCH2 may be allowed to bemultiplexed or prioritized if A<=C<=B or A<=D<=B.

The WTRU may determine that a second logical channel is within theminimum communication range of a first logical channel if the amount ofoverlap between the two minimum communication ranges associated with thefirst and second logical channels (e.g., as described above) is largerthan a threshold.

The WTRU may determine that a second logical channel is within theminimum communication range of a first logical channel if the distancebetween the respective minimum communication ranges of the secondlogical channel and the first logical channel is below a threshold(e.g., a preconfigured threshold). The distance between these minimumcommunication ranges may be measured as the distance between the lowerbounds (e.g., the distance between A and C in the example above), as thedistance between the upper bounds (e.g., the distance between B and D inthe example above), as the distance between two edges (e.g. the distancebetween B and C if B<C, or the distance between D and A if D<A in theexample above), or as the distance between the midpoints of the ranges(e.g., the distance between the midpoint of A and B and the midpoint ofC and D in the example above).

The WTRU may determine that a second logical channel is within theminimum communication range of a first logical channel if the respectiveminimum communication ranges of the two LCHs share at least one commonendpoint (e.g., A=C or B=D in the example above).

The WTRU may determine that a second logical channel is within theminimum communication range of a first logical channel if the minimumcommunication range of the second LCH falls completely inside theminimum communication range of the first LCH (e.g., A<=C and D<=B usingthe example above, etc.).

An LCH may be configured with a list of allowable minimum communicationrange values (e.g., in addition to or in lieu of a range). For example,an LCH may be configured with a list of minimum communication rangevalues. Such a list of minimum communication range values may correspondto the set of minimum communication range requirements (e.g., specificminimum communication range values) for one or more (e.g., all) QoSflows mapped to a corresponding SLRB. A WTRU may be configured with alist of minimum communication range values such as (10m, 100m, 200m).The WTRU may multiplex QoS flows with a minimum communication rangerequirement that matches one or more (e.g., any) of the listed values.The WTRU may select a first logical channel and may determine that asecond logical channel is within the minimum communication range of thefirst logical channel based on one or more of the following.

The WTRU may determine that the second logical channel is within theminimum communication range of the first logical channel if a (e.g.,any) value in the list of minimum communication range values for thefirst logical channel matches a value in the list of minimumcommunication range values for the second logical channel.

The WTRU may determine that the second logical channel is within theminimum communication range of the first logical channel if at least xminimum communication range values (e.g., x can be preconfigured orpredetermined) for the first logical match corresponding x minimumcommunication range values configured for the second logical channel.

The WTRU may determine that the second logical channel is within theminimum communication range of the first logical channel if at least onevalue in the list of minimum communication range values for the secondlogical channel is numerically between two minimum communication rangevalues configured for the first logical channel.

The WTRU may determine that the second logical channel is within theminimum communication range of the first logical channel if at least onevalue in the list of minimum communication range values for the secondlogical channel is a distance, y, away from at least one value in thelist of minimum communication range values for the second logicalchannel, where y is below a threshold (e.g., a preconfigured threshold).

The WTRU may determine that the second logical channel is within theminimum communication range of the first logical channel if multiple(e.g., all) minimum communication range values in the list of minimumcommunication range values for the first logical channel matchcorresponding minimum communication range values (e.g., all of theminimum communication range values) for the second logical channel.

The WTRU may determine that the second logical channel is within therange of minimum communication range of the first logical channel if theminimum communication range values configured for the second logicalchannel is a subset of the minimum communication range values configuredfor the first logical channel.

A WTRU may assign an associated minimum communication range for a grant,e.g., upon selection of a first LCH. The associated minimumcommunication range may be the lower bound minimum communication rangevalue in the set of minimum communication range values configured forthat LCH. The associated minimum communication range may be the upperbound minimum communication range value in the set of minimumcommunication range values configured for that LCH. The associatedminimum communication range may be the midpoint minimum communicationrange value of the set of minimum communication range values configuredfor that LCH. The associated minimum communication range may be anyminimum communication range value within the set of minimumcommunication range values configured for the LCH.

A WTRU may determine that a second LCH can be multiplexed into a PDU(e.g., a PDU comprising data from a first LCH) if one or more of thefollowing are within a distance x (e.g., x may be preconfigured orpredetermined) of an assigned minimum communication range for the grant.For example, the WTRU may determine that the second LCH can bemultiplexed into the PDU if the upper bound of the minimum communicationrange values of the second LCH is within distance x of the assignedminimum communication range for the grant. The WTRU may determine thatthe second LCH can be multiplexed into the PDU if the lower bound of theminimum communication range values of the second LCH is within distancex of the assigned minimum communication range for the grant. The WTRUmay determine that the second LCH can be multiplexed into the PDU if themidpoint of the minimum communication range values of the second LCH iswithin distance x of the assigned minimum communication range for thegrant. The WTRU may determine that the second LCH can be multiplexedinto the PDU if any value within the minimum communication range valuesconfigured for the second LCH is within distance x of the assignedminimum communication range for the grant.

A WTRU may be configured with a set of allowable or possible minimumcommunication range values. Once the WTRU selects a first LCH, the WTRUmay identify one of the allowable or possible values based on theminimum communication range(s) of the LCH. The WTRU may then berestricted to or may prioritize LCHs that are associated with theidentified allowable or possible range (e.g., as identified based on thefirst selected LCH). The WTRU may identify or associate an allowable orpossible range with a LCH based on one or more of the following.

The WTRU may identify or associate an allowable or possible range with aLCH based on whether a minimum communication range, set of minimumcommunication range values or list of minimum communication range valuesassociated with the LCH falls within the allowable configured range. Forexample, a configured allowable range may be [50m 100m] and a LCHassociated with a minimum communication range of [60m 80m] would beassociated with such a range.

The WTRU may identify or associate an allowable or possible range with aLCH based on whether one or more elements in the list of configuredminimum communication ranges for the LCH fall within the configuredallowable range.

The WTRU may identify or associate an allowable or possible range with aLCH based on whether there is an overlap between the configuredallowable minimum communication range and the minimum communicationrange(s) configured for the LCH, as described herein.

A WTRU may continue LCP by selecting LCHs (e.g., selecting only thoseLCHs) that are in the range of a first LCH. Comparison may be madebetween the LCH being considered and the first LCH selected. In examples(e.g., at the selection of each LCH), a WTRU may consider one or more(e.g., all) LCHs selected up to that point to decide whether a LCH beingconsidered can be included in a PDU. For example, the WTRU may includean LCH if it is within the range of one or more (e.g., any) alreadyselected LCHs based on the rules illustrated in the examples above. TheWTRU may include an LCH if it is within the range of one or more (e.g.,at least x, where x may be preconfigured) already selected LCHs based onthe rules illustrated in the examples above.

The WTRU may first select logical channels that fall within a certainset of minimum communication ranges and may satisfy each of theselogical channels up to their respective bucket sizes. If all logicalchannels in the minimum communication ranges have their bucket sizesatisfied and there is still space remaining in the grant, the WTRU mayselect logical channels outside of the minimum communication ranges.Such selection may also be based on one or more other criteria discussedherein (e.g. priority, Bj>0, etc.).

A WTRU may select the logical channels for a LCP based on a combinationof one or more QoS parameters including a minimum communication range. AWTRU may determine the logical channels to be multiplexed in a grantbased on a combination of bucket size, priority, and/or minimumcommunication range, as illustrated below.

A WTRU may select one or more highest priority logical channels havingBj>0, and may satisfy the logical channels of that priority up to theirrespective Bj's as long as the minimum communication range(s) of thoselogical channels fall within a certain range. In examples, logicalchannels outside a minimum communication range and having Bj>0 may besatisfied after logical channels with the highest priority and withinthe minimum communication range are satisfied. In examples, logicalchannels (e.g., of any priority) within a minimum communication rangemay be satisfied after the Bj's of one or more (e.g. all) logicalchannels (e.g., of any priorities) have been satisfied.

A WTRU may select one or more highest priority logical channels havingBj>0, and may further select those logical channels that fall within acertain minimum communication range so that the total value of Bj>0 forsuch logical channels (e.g., which have the same priority) may bemaximized.

A WTRU may select a set of logical channels having Bj>0 (e.g., with anypriority), and may further select those logical channels that fallwithin a certain minimum communication range so that the total value ofBj>0 or a weighted value of Bj>0 for the list of selected logicalchannels may be maximized. The weight used to calculate the weightedvalue of Bj may be linked to (e.g., based on) the priority of eachcorresponding logical channel.

A WTRU may restrict or prioritize the multiplexing of SDUs associatedwith MCR range separately from the multiplexing of SDUs not associatedwith a minimum communication range. For example, the WTRU may multiplexthe SDUs associated with a minimum communication range together andmultiplex the SDUs not associated with a minimum communication rangetogether (e.g., separately from the multiplexing of the SDUs associatedwith a minimum communication range). A WTRU may multiplex logicalchannels associated with a minimum communication range up to thesatisfaction of another QoS parameter (e.g., such as bucket size) andthen consider multiplexing logical channels not associated with aminimum communication range if there is additional space in a grant. AWTRU may multiplex logical channels not associated with a minimumcommunication range up to the satisfaction of another QoS parameter(e.g., such as bucket size) and then consider multiplexing logicalchannels associated with a minimum communication range if there isadditional space in a grant.

LCP restriction associated with MCR range may be applied when (e.g.,only when) a first transmission selected has a minimum communicationrange that is below or above a threshold. For example, if a WTRU selectsdata for a first LCH associated with a first minimum communication rangeand the first minimum communication range is below a threshold, the WTRUmay restrict the selection of other LCHs such that they fall within aminimum communication range or minimum communication ranges associatedwith the first LCH. If the WTRU selects a transmission with a minimumcommunication range above a threshold, the WTRU may select a LCH (e.g.,any LCH regardless of the associated minimum communication range)without minimum communication range restrictions.

LCP restriction associated with a minimum communication range maycomprise a WTRU selecting one or more LCHs that have a minimumcommunication range value equal to or less than the minimumcommunication range value associated with a first LCH selected. Forexample, the WTRU may select a first LCH based on other criteria (e.g.,criteria unrelated to minimum communication range). The WTRU may (e.g.,following such selection) select (e.g., only select) LCHs that have aminimum communication range value equal or less than the minimumcommunication range value associated with the first selected LCH.

A WTRU may decide whether to multiplex LCH with and without a rangerestriction.

A WTRU may be configured with LCHs with a minimum communication rangeand/or LCHs without a minimum communication range. For certain LCHs(e.g., those associated with groupcast), QoS flows with minimumcommunication range requirements may be grouped together, while forother LCHs (e.g., which may also be associated with groupcast), QoSflows without minimum communication range requirements may be groupedtogether. The WTRU may have one or more of the following behaviors whenperforming LCP in the presence of LCHs with or without a configuredminimum communication range or set of minimum communication ranges.

The WTRU may be configured to not multiplex an LCH with a configuredminimum communication range with an LCH without a configured minimumcommunication range. In examples (e.g., where an allowable range isdetermined by a first selected LCH, as described herein), if the WTRUselects a LCH that does not have a configured minimum communicationrange or set of minimum communication ranges, the WTRU may select (e.g.,only select) other LCHs (e.g., for multiplexing) that also do not have aconfigured minimum communication range or set of minimum communicationranges. If the WTRU selects a LCH that has a configured minimumcommunication range or set of minimum communication ranges, the WTRU mayselect (e.g., only select) other LCHs (e.g., for multiplexing) that alsohave a configured minimum communication range or set of minimumcommunication ranges.

The WTRU may be configured to multiplex an LCH having a configuredminimum communication range with an LCH that does not have a configuredminimum communication range, for example, based on the specific minimumcommunication range or set of minimum communication ranges associatedwith LCH having a configured minimum communication range or set ofminimum communication ranges. For example, if the WTRU selects a LCHthat has a configured minimum communication range or set of minimumcommunication ranges, the WTRU may select one or more other LCHs (e.g.,for multiplexing) that do not have a configured minimum communicationrange or set of minimum communication ranges as long as the minimumcommunication range or set of minimum communication ranges of the firstselected LCH is large enough (e.g., based on the absolute minimumcommunication range value of one or more minimum communication ranges inthe configured set), small enough (e.g., based on the absolute minimumcommunication range value of one or more minimum communication ranges inthe configured set), wide enough (e.g., based on the size of the range),or narrow enough (e.g., based on the size of the range). If the WTRUselects a LCH that does not have a configured minimum communicationrange or set of minimum communication ranges, the WTRU may select one ormore other LCHs (e.g., for multiplexing) with a configured minimumcommunication range or set of minimum communication ranges as long asthe LCHs satisfy similar conditions as described above.

A WTRU may be configured to multiplex a LCH having a configured minimumcommunication range with a LCH that does not have a configured MINIMUMCOMMUNICATION RANGE based on the distance between the minimumcommunication range(s) configured for one or more (e.g., each) of theQoS flows that are currently multiplexed with the LCH that does not havea configured minimum communication range. If the WTRU selects an LCHwithout a configured minimum communication range, the WTRU may decidewhether the distance between the lowest minimum communication range QoSflow and largest minimum communication range QoS flow is larger than athreshold. If the distance is larger than the threshold, the WTRU maydecide not to multiplex an LCH with a configured minimum communicationrange into the same PDU. Otherwise, the WTRU may decide to multiplex anLCH with a configured minimum communication range into the same PDU. TheWTRU may determine the allowable minimum communication range(s) asillustrated by the examples provided herein.

A WTRU may determine whether to multiplex a LCH having a configuredminimum communication range with a LCH that does not have a configuredminimum communication range based on the actual QoS flows (e.g., and/ortheir associated minimum communication range) that have been mapped to aLCH. For example, the WTRU may select a LCH (e.g., a first LCH) withouta configured minimum communication range or set of minimum communicationranges. The WTRU may determine the QoS flows that have been mapped tothe LCH and their corresponding MCR range(s). The WTRU may determinewhether a LCH (e.g., a second LCH) with a configured MCR range can bemultiplexed into the PDU by considering one or multiple MCR rangesassociated with the flows multiplexed into the first LCH, and applyingthe rules described herein to determine whether the second LCH is withinthe range of the first LCH (e.g., based on whether the minimumcommunication range of the second LCH includes the minimum communicationrange configured for one or more QoS flows mapped to the first LCH).

A WTRU may select an LCH configured with a minimum communication rangeor set of minimum communication ranges. The WTRU may then determinewhether to multiplex a LCH without a configured minimum communicationrange based on the actual minimum communication range value associatedwith the flows multiplexed into the LCH without a minimum communicationrange requirement.

FIG. 3 illustrates a destination selection procedure 300 that may beexecuted a WTRU. The procedure 300 may be performed by the WTRU (e.g.,periodically) at 302. At 304, the WTRU may determine that a set ofsidelink resources are available for the WTRU to perform a sidelinktransmission. As described herein, the set of sidelink resources may beconfigured or scheduled by a network (e.g., in Mode 1) or the set ofsidelink resources may be selected autonomously by the WTRU (e.g., fromone or more preconfigured resource pools). The set of resources mayinclude time and/or frequency resources, and/or may be configuredspecifically for sidelink transmission. In response to determining thatthe set of resources have become available, the WTRU may, at 306,identify one or more logical channels (LCHs) that have a bucket sizeparameter meeting a certain criterion. For example, the WTRU mayidentify the one or more logical channels that have Bj>0. Uponidentifying the one or more logical channels having Bj>0, the WTRU mayfurther select, from the identified logical channels, the logicalchannel(s) that have the highest transmission priority.

At 308, the WTRU may determine the respective destinations associatedwith the selected logical channels (e.g., the selected highest logicalchannel(s) having Bj>0). If the WTRU determines, at 310, that there aremultiple destinations associated with logical channels that satisfy thecriteria described above, the WTRU may, at 312, select the destinationto which transmission may minimize the amount of resources used for datathat exceed the Bj of the logical channels associated with thedestination (e.g., transmission to the selected destination may resultin the least amount of resources being used for data exceeding the Bj ormay result in the maximum amount of resources being used to satisfy theBj). If the WTRU determines, at 310, that there is only destination withlogical channels that satisfy the criteria described above, the WTRUmay, at 314, select a first LCH (L1) associated with the destinationthat has the highest priority and Bj>0 and allocate at least a portionof the available resources to the transmission of L1 (e.g., to satisfythe Bj of L1) at 316.

At 318, the WTRU may check whether there are extra resources left fortransmission. If there are resources left, the WTRU may select anadditional LCH (Lx) for transmission (e.g., to be multiplexed with thetransmission of L1) at 320 based on one or more of a priority, a bucketsize related parameter (e.g., Bj) or a minimum communication range (MCR)associated with the additional LCH (Lx). For example, the WTRU mayselect an additional LCH that has the next highest priority (e.g., amongthe remaining logical channels associated with the destination), hasBj>0, and/or has a minimum communication range that is within a distanceof the minimum communication range of the first logical channel L1(e.g., distance (MCR (L1), MCR(Lx))<threshold, where the threshold maybe configured/signaled by a network or determined by the WTRU). Uponselecting such an additional LCH (Lx), the WTRU may allocate at least aportion of the available resources to the transmission of Lx (e.g., tosatisfy the Bj of Lx). The transmission of L1 and Lx may be multiplexedtogether (e.g., in the same PDU). The WTRU may repeat the operations at318-322 until there are no more resources left, up which the WTRU mayend the destination selection procedure 300 at 324.

A WTRU may determine the minimum communication range to be transmittedin SCI or sent to L1. In examples (e.g., following LCP), a WTRU maydetermine a minimum communication range value to be transmitted in SCI.Such a minimum communication range may be transmitted explicitly or maybe combined with other QoS parameters into a L1 QoS parameter (e.g.,such as L1 priority). The value of the L1 QoS parameter may beassociated with a specific minimum communication range and/or other QoSparameters such as one or more reliability, latency, or priority relatedparameters.

A WTRU may determine the minimum communication range to be sent to L1based on one or more of the following. The WTRU may use one or more ofthe minimum communication range or set of minimum communication rangesassociated with a LCH configured with the largest minimum communicationrange or largest list of minimum communication range values. The WTRUmay use the largest upper bound minimum communication range valueassociated with a set of LCHs multiplexed into a PDU. The WTRU may usethe largest lower bound minimum communication range value associatedwith a set of LCHs multiplexed into a PDU. The WTRU may use the largestmidpoint minimum communication range value associated with a set of LCHsmultiplexed into a PDU. The WTRU may use the largest minimumcommunication range (e.g., a single minimum communication range value)configured for any of the LCHs multiplexed into a PDU. The WTRU may usethe largest minimum communication range among the list of minimumcommunication ranges configured for one or more (each) of the LCHsmultiplexed into a PDU. The WTRU may use the largest minimumcommunication range associated with one or more (e.g., any) QoS flowsmapped to a (e.g., any) LCH multiplexed into the PDU.

A WTRU may be configured to select from a plurality of candidate values(or combination thereof) a suitable value for a transmission parameter.Minimum communication range, data rate and/or fairness requirements maybe satisfied based on the respective values a WTRU selects for one ormore transmission parameters.

A transmission parameter value may be selected based on the dataavailable for transmission, based on a property of the data, arequirement associated with the data, and/or a variable associated withthe data. For example, a transmission parameter value may be selectedbased on the minimum communication range of a logical channel (or a MACSDU) for which there is data available for transmission. A transmissionparameter value may be selected based on one or more parameters orvariables used in LCP, such as a bucket variable for a logical channel jrepresenting a buck size associated with the logical channel (Bj), aprioritized bit rate (PBR), and/or a logical channel priority. Atransmission parameter value may be selected based on the identity of aWTRU or a group of WTRUs intended to receive the data available fortransmission.

The data or LCH used for parameter selection may be determined asfollows. A WTRU may determine the data or logical channel as a functionof which parameter selection is performed. A WTRU may consider a set oflogical channels that meet one or more the following conditions. A WTRUmay consider a logical channel that has data available for transmission.A WTRU may consider a logical channel that for which a variable Bj(e.g., representing a buck size associated with the logical channel)used in LCP is above a specific threshold (e.g., zero).

One or more of the conditions described above (e.g., the secondcondition described above) may service to ensure the fairness oftransmission, e.g., since the conditions may prevent the use ofresources beyond what is required to meet a quality requirement (e.g., adata rate requirement) of the logical channel. A WTRU may restrict theselection of logical channels to a logical channel that has the highestpriority among all logical channels meeting a given condition.

A WTRU may determine a target minimum communication range that may beused in the determination of transmission parameters and/or ingenerating a report for the network. The target minimum communicationrange may be, for example, the highest minimum communication range level(or value) among multiple minimum communication range values associatedwith a logical channel(s) (e.g., as determined above) or with a MAC SDUavailable for transmission.

In examples (e.g., when network-controlled operation is supported, as innetwork scheduled mode, e.g., Mode 1), a WTRU may signal a targetminimum communication range to the network, for example, via physicallayer and/or MAC layer signaling. A WTRU may include a target minimumcommunication range in an enhanced buffer status report. A WTRU maytrigger transmission of a MAC control element (or an enhanced BSR) whenthere is a change in the target minimum communication range. In examples(e.g., when no PUSCH resources are available), a WTRU may transmit atarget minimum communication range in a physical layer signal such as ascheduling request. A WTRU may report a target maximum communicationrange.

A WTRU may decrease a target minimum communication range to a levellower than the minimum communication range level associated with thedata available for transmission, for example, if there is no intendedreceiver beyond a certain communication range lower than that minimumcommunication range level. A WTRU may obtain the location of an (e.g.,each) intended receiver (e.g., through higher layer signaling) and maydetermine a maximum distance among the intended receivers. A WTRU mayobtain a path loss estimate for an (e.g., each) intended receiver andmay determine a maximum path loss among the intended receivers. Suchestimation may be performed and reported by the intended receivers, orbe performed directly by the WTRU (e.g., based on the signaling of knowntransmission power).

Transmission parameters (e.g., MCS) may be selected to maximize a metric(e.g., spectral efficiency). A WTRU may select a combination oftransmission parameters within a candidate set that meet at least one ofthe following conditions. A WTRU may select a combination oftransmission parameters such that the transmission is suitable for atarget minimum communication range. A WTRU may select a combination oftransmission parameters such that a metric (as described herein) ismaximized or minimized.

The attempted maximization (or minimization) of a metric may be used toattempt to maximize spectral efficiency and/or minimize transmissionpower. The attempted maximization (or minimization) may be realized invarious ways, e.g., depending on how a WTRU selects transmissionparameters.

A WTRU may be configured to select a modulation and coding scheme (MCS)from a configured set or range of MCS values. A WTRU may select thehighest MCS value for which a transmission is suitable. A WTRU mayselect the minimum or maximum table index entry from a parameter table(e.g., from a MCS table) if the table is ordered by MCS values. A WTRUmay select an MCS such that the required transmission power suitable fora target minimum communication range is maximized while still below theactual transmission power of the WTRU (e.g., which may be setindependently).

A WTRU may be configured to select a combination of MCS and transmissionpower levels from a configured (e.g., pre-defined) set of candidatecombinations. Such combinations may be ordered, for example, based onthe highest MCS levels in a descending order such that a transmissionmay be suitable. A WTRU may select the highest value such that atransmission is suitable for a target MCS and/or that the transmissionpower level is lower than a maximum power level configured for the WTRU(e.g., a maximum power level configured by an independent power controlmechanism).

A WTRU may determine candidate resources based on a target transportblock size. A WTRU may be configured to select resources (e.g., infrequency and/or time domain) for a grant from a plurality of candidateresources. The set of candidate resources may be such that differentcandidate resources may occupy different number of resource blocks, timeslots, and/or symbols. The set of candidate resources may be restrictedby factors such as channel occupancy, as described herein.

A WTRU may determine a transport block size for each candidate resourcebased on frequency allocation, time allocation, and/or other parameterssuch as MCS. The MCS may in return be determined, for example, based ona target minimum communication range as described herein.

A WTRU may select a candidate resource such that the amount of usedresources may be minimized and/or QoS requirements (e.g., data rate) maybe satisfied. A WTRU may determine a target transport block size as thesmallest transport block size such that at least one of the followingconditions may be satisfied for at least one logical channel (e.g.,after LCP is performed for MAC PDUs or transport blocks): no data may beavailable for transmission for the at least one logical channel or avariable Bj (e.g., which may represent a buck size associated withlogical channel j) associated with the at least one logical channel andused in LCP is below a threshold (e.g., zero). Other conditions may alsobe selected and the selection of the conditions may depend on theconcerned logical channel(s).

Once a target transport block size is determined, a WTRU may restrictthe set of candidate resources to those for which the correspondingtransport block size is the smallest while still above the targettransport block size. This approach may ensure that the WTRU does notuse resources beyond what is required to satisfy a given QoSrequirement.

A WTRU may make a best effort when transmitting beyond a certain minimumcommunication range (e.g., a minimum communication range configured fora specific flow, bearer, and/or transmission). For example, the WTRU mayuse best-effort transmission parameters (e.g., best or optimaltransmission parameters available to the WTRU) if a receiving device(e.g., a receiving WTRU) is located outside the minimum communicationrange.

To illustrate, a WTRU engaging in V2X transmission may modify one ormore aspects of the WTRU's sidelink transmission parameters based onwhether a receiving device (e.g., an RX WTRU) is within or outside of acertain minimum communication range (e.g., a minimum communication rangeconfigured for a specific flow, bearer, and/or transmission). The WTRU(e.g., a transmitting or TX WTRU) may operate with optimal transmissionparameters targeted to meet the QoS requirements of a transmission whensuch transmission is associated with a minimum communication range and aWTRU receiving the transmission is located within the minimumcommunication range. On the other hand, if the transmission isassociated with a minimum communication range and a WTRU receiving thetransmission is located outside of the minimum communication range, thetransmitting WTRU may switch to parameters that are not intended to meetthe aforementioned QoS requirements. Such QoS requirements may berelated to at least latency, priority, data rate, and/or reliability.

A receiving WTRU (e.g., an RX WTRU) may provide an indication of itslocation and/or whether the WTRU is located inside or outside of aminimum communication range, for example, via SCI or a sidelink controlmessage.

A receiving WTRU may transmit its location, or indicate a change in itslocation via a control message. A transmitting WTRU may determinewhether a receiving WTRU is within the minimum communication range for aspecific transmission based on the reception of such control message.Such control message may comprise dedicated SCI, SL MAC CE, feedbackinformation, or SL RRC message. The control message may comprisegeolocation information, zone or subzone index, indication of a changein location, or similar information for the receiving WTRU. For example,the control message may comprise location information of the receivingWTRU such as geolocation coordinates, zone ID, subzone ID, and/or thelike. The control message may comprise an indication of whether thereceiving WTRU is within or outside a certain minimum communicationrange (e.g., a minimum communication range associated with a specificSLRB). The control message may comprise one or more SLRB IDs for whichthe receiving WTRU is inside or outside a certain minimum communicationrange. The control message may comprise link feedback relatedinformation such as HARQ feedback, CQI reports, etc. The control messagemay comprise a WTRU ID, a unicast link ID, and/or the like.

A WTRU may determine whether to transmit its location information basedon a configuration (e.g., based on SL bearer configuration). Forexample, a receiving WTRU may receive a SL bearer configuration for aunicast link from a transmitting WTRU. The configuration may explicitlyconfigure periodic location transmission at the receiving WTRU. Thereceiving WTRU may determine whether and/or when to transmit locationinformation based on a bearer configuration associated with thetransmitting WTRU, based on the location of the receiving WTRU, and/orbased on a transmission characteristic of the transmitting WTRU.

A receiving WTRU may respond to a feedback request (e.g., sent by atransmitting WTRU) when the receiving WTRU is within a certain minimumcommunication range. The receiving WTRU may transmit feedbackinformation when (e.g., only when) the WTRU is within a certain minimumcommunication range. A feedback request by a transmitting WTRU may beimplicitly sent based on the transmission of a reference signal (e.g.,when the transmitting WTRU includes CSI-RS in its transmission). Forexample, a transmitting WTRU may transmit an RRC request message (e.g.,such as a maintenance message) and a receiving WTRU may respond (e.g.,only respond) to the maintenance message when the receiving WTRU iswithin a certain minimum communication range. The receiving WTRU maydetermine that it is within the configured minimum communication rangebased on a bearer configuration, the location of the transmitting WTRU(e.g., which may be indicated in the transmitting WTRU's transmissionsuch as a CQI request), and/or the receiving WTRU's own locationinformation. For example, a receiving WTRU may compute the distancebetween itself and a transmitting WTRU based on the location informationof the transmitting WTRU (e.g., as indicated in a CQI request) and thereceiving WTRU's own location. If this distance is smaller than theminimum communication range associated with a SLRB configured by thetransmitting WTRU, the receiving WTRU may respond to a feedback requestby the transmitting WTRU. Otherwise, the receiving WTRU may ignore thefeedback request.

A transmitting WTRU may signal an applicable minimum communicationrange, for example, in a feedback request. Such a feedback request maybe specific to a particular minimum communication range. A receivingWTRU may send feedback when (e.g., only when) the receiving WTRUdetermines that it is within the minimum communication range associatedwith the feedback request. The transmitting WTRU may transmit theminimum communication range associated with a feedback requestexplicitly in a feedback request message. A CQI request, a datatransmission including CSI-RS, or another feedback request sent by thetransmitting WTRU may include an explicit indication of the minimumcommunication range for which feedback is expected. Sidelink controlinformation associated with a CQI request or a data transmission mayalso include such an explicit indication.

A receiving WTRU may determine an applicable minimum communicationrange, for example, based on data multiplexed with a transmission by thetransmitting WTRU. The receiving WTRU may determine the LCH(s) orSLRB(s) comprised in such a transmission. The receiving WTRU may treatthe minimum communication range of a feedback request provided with sucha transmission as the worst case (e.g., largest) minimum communicationrange configured with one or more (e.g., each) of the transmitted SLRBs.

A WTRU (e.g., a transmitting WTRU) may transmit (e.g., signal) an offset(e.g., a distance) from the minimum communication range associated witha data transmission and a receiving WTRU may apply the offset indetermining the minimum communication range associated with a feedbackrequest. A WTRU (e.g., a transmitting WTRU) may transmit an indicationto signal whether the minimum communication range associated with afeedback request should be associated with a data minimum communicationrange or another minimum communication range. Such other minimumcommunication range may be determined based on a SLRB configuration ofthe transmitting WTRU (e.g., a SLRB with the largest minimumcommunication range). A WTRU (e.g., a transmitting WTRU) may transmit aSLRB or LCH index in a feedback request and a receiving WTRU maydetermine an applicable minimum communication range for the feedbackrequest based on the minimum communication range configured with thatSLRB or LCH.

A receiving WTRU may transmit an indication of its location when theWTRU moves into or out of a minimum communication range. The receivingWTRU may transmit an event-triggered control message when it transitionsfrom being inside (or outside) the minimum communication range of atleast one or more SLRB to being outside (or inside) the minimumcommunication range of the one or more SLRB. The receiving WTRU maydetermine its distance from a transmitting WTRU based on locationinformation included in a data or control transmission of thetransmitting WTRU and the receiving WTRU's own location. The receivingWTRU may determine the minimum communication range informationassociated with a SLRB based on SLRB configuration information (e.g.,which may be sent via SL RRC signaling).

A receiving WTRU may (e.g., periodically) transmits location informationbased on a SLRB configuration. For example, the receiving WTRU maydetermine to periodically transmit location information when the SLbearer configuration of a transmitting WTRU includes at least one SLRBconfigured with a range requirement. The receiving WTRU may receive theSL bearer configuration of the transmitting WTRU via SL RRC messagingassociated with unicast and/or groupcast link establishment ormodification. The receiving WTRU may transmit such periodic locationinformation when the WTRU determines that it is within the minimumcommunication range of at least one SLRB, as described herein.

A receiving WTRU may transmit HARQ feedback along with a transmissionrange indication.

In examples (e.g., for a unicast SL groupcast transmission), a WTRU maynot transmit a HARQ feedback for a PSSCH transmission when the TX-RXdistance associated with the PSSCH transmission is larger than thatspecified by a communication range requirement such as a minimumcommunication range requirement (e.g., the PSSCH transmission is outsideof the minimum communication range). In these cases, the transmittingWTRU may observe HARQ discontinuous transmissions (DTX) in theassociated physical sidelink feedback channel (PSFCH) (e.g., thetransmitting WTRU may receive no HARQ ACK/NACK).

A transmitting WTRU may perform a HARQ re-transmission upon receiving aHARQ DTX (e.g., because the HARQ DTX may indicate that a receiving WTRUmay have failed to decode the PSCCH). In these cases, a transport block(TB) may be correctly received and a HARQ re-transmission may notactually be necessary. A HARQ DTX outside a minimum communication rangemay be distinguished from other HARQ DTX transmissions to avoid orreduce unnecessary HARQ re-transmissions.

In examples (e.g., for a group transmission with HARQ enabled), a WTRUmay transmit a HARQ feedback including HARQ ACK/NACK information and/oran out-of-minimum communication range indicator. For instance, the WTRUmay transmit one or more additional bits in the HARQ feedback payload toindicate whether the HARQ feedback information pertains to a TB receivedwithin a minimum communication range (MCR). A transmitting WTRU mayreceive the HARQ feedback with the minimum communication range indicatorand may perform a HARQ re-transmission, e.g., in accordance with theexample rules illustrated in the table below. When no HARQre-transmission is performed, a transmitting WTRU may flush its HARQbuffer. The transmitting WTRU may apply “best effort” transmissionssubsequently, e.g., based on configured (e.g., preconfigured)transmission parameters for WTRUs that are outside of the minimumcommunication range.

WTRU HARQ re- HARQ feedback payload transmission HARQ ACK + in-MCR    NoHARQ NACK + in-MCR    Yes HARQ ACK + out-of-MCR No HARQ NACK +out-of-MCR  No

The HARQ feedback payload comprising a transmission range indicator asdescribed herein may use reserved cyclic shifts. For example, fourcyclic shift values of a sequence may be configured, reserved, and/orused. One or more of the cyclic values may be selected or determinedbased on the HARQ feedback payload.

Example sets (e.g., three sets) of cyclic shift values may include, forexample, Set-1: {0, 3, 6, 9}, Set-2: {1, 4, 7, 10}, and Set-3: {2, 5, 8,11}.

A set of cyclic shift values may be determined based on one or more offollowing. The cyclic shift values may be determined based on thesubchannel index (e.g., the first subchannel index) of an associatedPSSCH/PSCCH transmission. A set of cyclic shift values may be determinedbased on the number of subchannels. A set of cyclic shift values may bedetermined based on the number of PSFCH resources within a slot.

Example cyclic shift value assignments for each HARQ feedback payloadwithin a set may be as illustrated in the table below.

HARQ feedback payload Cyclic shift value of PSFCH HARQ ACK + in-MCR   1^(st) cyclic shift value HARQ NACK + in-MCR    3^(rd) cyclic shiftvalue HARQ ACK + out-of-MCR 2^(nd) cyclic shift value HARQ NACK +out-of-MCR  4^(th) cyclic shift value

In examples (e.g., when multiple HARQ-ACK bits are multiplexed), thein-MCR and/or out-of-MCR status of a transmission may be indicated in aHARQ-ACK transmission. In examples, if the number of HARQ-ACK bitsexceeds a threshold, a receiving WTRU may not include an in-MCR orout-of-MCR indicator in the HAR-ACK transmission.

Separate PSFCH resource pools may be used for in-MCR and out-of-MCRtransmissions. For example, a first PSFCH resource pool may be used whena receiving WTRU is in-MCR and a second PSFCH resource pool may be usedwhen the receiving WTRU is out-of-MCR. The one or more PSFCH resourcepools may be multiplexed in the frequency domain, for example, so that areceiving WTRU may report HARQ feedback in the same slot irrespective ofthe in-MCR or out-of-MCR status of the WTRU. One or more of followingmay apply.

A transmitting WTRU may not retransmit a sidelink transmission if theWTRU receives HARQ feedback in an out-of-MCR PSFCH resource pool.

An in-MCR PSFCH resource pool may be configured without an associatedout-of-MCR PSFCH resource pool. When an out-of-MCR PSFCH resource poolis not configured, a receiving WTRU may not send HARQ-ACK when the WTRUis out-of-MCR.

If both in-MCR PSFCH and out-of-MCR PSFCH resource pools are configured,a receiving WTRU may send HARQ feedback irrespective of the in-MCR orout-of-MCR status of the WTRU.

A transmitting WTRU may determine whether one or more receiving WTRUsare within a minimum communication range. The transmitting WTRU may makethe determination based on a location indication provided by the one ormore receiving WTRUs, as discussed herein. For example, the transmittingWTRU may transmit a request message (e.g., such as an RRC maintenancemessage, a CQI request, etc.) destined to one or more receiving WTRU.Based on the presence of a response message and/or location informationincluded in the response message, the transmitting WTRU may determinewhether one or more receiving WTRUs are within the minimum communicationrange associated with a bearer.

A transmitting WTRU may use the transmissions of a receiving WTRU (e.g.,which may include location information of the receiving WTRU) todetermine whether the receiving WTRU is within a minimum communicationrange. For example, a transmitting WTRU may receive one or moretransmissions by a receiving WTRU that include the location informationof the receiving WTRU. The transmitting WTRU may determine the distancebetween itself and the receiving WTRU based on this location informationand the transmitting WTRU's own location. If the distance is smallerthan the minimum communication range associated with a packet, flow orSLRB, the transmitting WTRU may determine that the receiving WTRU iswithin the minimum communication range associated with that packet,flow, or SLRB. A transmitting WTRU may determine whether a receivingWTRU is within a minimum communication range based on reception of HARQfeedback from that receiving WTRU. The receiving WTRU may be configuredwith HARQ feedback resource(s) on which to transmit ACK/NACK. If thetransmitting WTRU observes one or more (e.g., consecutive) DTX on suchresource(s), the transmitting WTRU may assume that the receiving WTRU isoutside the minimum communication range associated with the transmittingWTRU's transmissions.

A transmitting WTRU may determine a receiving WTRU associated with aunicast or groupcast session based on one or more of the following.

A transmitting WTRU may determine a receiving WTRU associated with aunicast or groupcast session based on link establishment signaling. Forexample, the transmitting WTRU may obtain the WTRU ID of a peerreceiving WTRU during unicast link establishment signaling and/orexchange. The transmitting WTRU may initiate unicast link establishmentsignaling with one or more (e.g., each) WTRUs in a group and maydetermine the list of WTRUs in a groupcast session based on response(s)associated with the unicast link establishment. The unicast linkestablishment may be initiated by an upper layer (e.g., a NAS layer)

A transmitting WTRU may determine a receiving WTRU associated with aunicast or groupcast session based on one or more upper layers. Forexample, the transmitting WTRU may obtain a list of WTRU IDs (e.g.,source WTRU IDs) associated with a groupcast session or a groupcastdestination ID based on information provided by an upper layer (e.g., aNAS layer, a V2X layer, and/or an application layer).

A WTRU may associate a minimum communication range with a LCH or a SLRB.A WTRU may determine the minimum communication range associated with aSLRB based on a network configuration (e.g., explicit signaling of theminimum communication range in a SLRB configuration). A WTRU maydetermine the minimum communication range associated with a SLRB basedon the minimum communication range configured for a (e.g., each) flowthat is mapped to the SLRB. For example, a WTRU may be configured with amapping (e.g., a mapping rule) between flows and SLRBs, and the WTRU maydetermine the minimum communication range of a SLRB as the worst case(e.g., largest) minimum communication range associated with all flowsmapped to that bearer.

A WTRU may assign a default value (e.g., Om) to a minimum communicationrange associated with a flow if the flow is not associated with aminimum communication range configured by an upper layer.

A transmitting WTRU may modify a transmission-related parameter for abearer or for transmissions associated with a minimum communicationrange. For example, a transmitting WTRU may modify atransmission-related parameter (e.g., a parameter associated with abearer) when the WTRU determines that one or more receiving WTRUs areoutside of a minimum communication range (e.g., a minimum communicationrange associated with the bearer). A transmitting WTRU may make such adetermination based on signaling and/or transmissions from a receivingWTRU as described herein. For example, a transmitting WTRU may use oneor more configured parameters to be used in a best effort scenario, asdescribed herein. Such best effort parameters may be fixed orpredetermined and/or may correspond to default values. A transmittingWTRU may use such configured or predetermined parameters in lieu ofconfigured parameters associated with a SLRB. For example, atransmitting WTRU may replace a SLRB configuration with one or more ofthe following configured or predetermined values when one or more (e.g.,all) transmitting WTRUs are outside of the minimum communication rangefor a SLRB.

A transmitting WTRU may use default or preconfigured variables orparameters in a LCP procedure. For example, the transmitting WTRU mayuse a different or a default value of PBR, BSR, or Bj during the LCPprocedure. The transmitting WTRU may set the Bj to 0 (or a similardefault value) for a SLRB or LCH. The transmitting WTRU may set theallowable BW, allowable number of resources, allowable number ofcarriers, etc. associated with resource selection to default, configuredor predetermined values. The transmitting WTRU may use a default ordifferent value of priority (e.g., as used in LCP) for a LCH. Thetransmitting WTRU may modify one or more LCP restrictions to allow ordisallow a LCH to be multiplexed with other LCHs. In examples, thetransmitting WTRU may be allowed to multiplex LCHs together if (e.g.,only if) the intended WTRUs are within the minimum communication rangeof at least one of the LCHs. In examples, the transmitting WTRU may beallowed to multiplex LCHs together if (e.g., only if) the intended WTRUsare outside of the minimum communication range of at least one of theLCHs.

A transmitting WTRU may use default or preconfigured variables orparameters for resource selection. For example, the transmitting WTRUmay set the resource selection window to a different value (e.g., forresource selection associated with LCHs where the intended WTRUs areoutside of the minimum communication range of at least one of the LCHs).The transmitting WTRU may set a parameter associated with a number ofresources to certain default or predetermined value for one or moresidelink processes. The number of resources may include those that theWTRU can reserve in advance or maintain following a reselection. The oneor more sidelink processes may be intended for LCHs where the intendedWTRUs are outside of the minimum communication range of at least one ofthe LCHs. The transmitting WTRU may be allowed to perform periodictransmissions if (e.g., only if) those transmissions include data forwhich the intended WTRUs are inside a certain minimum communicationrange. The transmitting WTRU may be configured with a different resourceavailability threshold.

A transmitting WTRU may use default or preconfigured values for one ormore PHY parameters. For example, the transmitting WTRU may settransmission parameters such as MCS, TX power, number ofretransmissions, and/or the like to default, predefined, or configuredvalues for transmissions associated with a LCH for which the intendedWTRUs are outside a certain minimum communication range. Thetransmitting WTRU may be allowed to perform duplication of transmissionsbased on whether such transmissions are associated with a LCH for whichthe intended WTRUs are inside a certain minimum communication range.

A transmitting WTRU may use default or preconfigured values for unicastor groupcast feedback configurations. For example, the transmitting WTRUmay disable HARQ feedback associated with a transmission for which theintended receivers (e.g., WTRUs) are outside of a certain minimumcommunication range. The transmitting WTRU may disable transmission ofCSI-RS when one or more receiving WTRUs are outside of a minimumcommunication range associated with one or more (e.g., any or all) LCHsor SLRBs.

A transmitting WTRU may modify a flow-to-bearer mapping for a flowassociated with a minimum communication range. For example, thetransmitting WTRU may change a flow-to-bearer mapping associated with aflow based on whether an intended receiving WTRU of the flow is withinor outside of a certain minimum communication range. The transmittingWTRU may map a flow for which at least one of the intended WTRUs arewithin the minimum communication range to a SLRB with QoS requirementsconfigured to meet one or more QoS requirements of the flow. Thetransmitting WTRU may map a flow for which at least one of the intendedWTRUs are outside of the minimum communication range to a default orbest effort SLRB. The default or best effort SLRB may be associated withsimilar parameters as the default, predefined, or configured parametersdiscussed herein that may be modified for a QoS specific SLRB.

A transmitting WTRU may consider one or more of the following factors(e.g., in addition to determining whether a receiving WTRU is outside ofa certain minimum communication range) when deciding whether to performa transmission using best effort SLRB and/or parameters.

A transmitting WTRU may consider measured congestion of one or more SLresources when deciding whether to perform a transmission using besteffort SLRB and/or parameters. For example, the transmitting WTRU may beconfigured with a threshold channel busy ratio and may decide to performa transmission using best effort parameters if the measured channel busyratio is above the threshold. The transmitting WTRU may be configured touse different SLRB configurations or parameters (e.g., different defaultconfigurations or parameters) based on a measured channel busy ratio.

A transmitting WTRU may consider the velocity of the transmitting WTRUand/or the relative motion between the transmitting WTRU and a receivingWTRU when deciding whether to perform a transmission using best effortSLRB and/or parameters. For example, the transmitting WTRU may beconfigured to perform a transmission using default SLRB configurationsand/or parameters when (e.g., only when) the WTRU's velocity is below athreshold or the relative velocity of the WTRU compared to one or moreother WTRUs (e.g., peer WTRUs) is below a threshold.

A transmitting WTRU may consider a network configuration when decidingwhether to perform a transmission using best effort SLRB and/orparameters. For example, the transmitting WTRU may be configured (e.g.,via SIB or RRC signaling) with an indication of whether to perform atransmission using default SLRB parameters. Such an indication may beimplicit (e.g., be included or indicated in the configuration of suchparameters by the network).

A WTRU may be configured to perform best effort transmission when theWTRU is beyond a minimum communication range.

A WTRU may be configured to favor (e.g., give higher priority to)transmissions with lower minimum communication range during congestioncontrol (e.g., in order to mitigate congestion).

A WTRU may operate with different sets of congestion-controlled TXparameters based on the range requirements (e.g., minimum communicationrange) of the transmission (e.g., data transmission). For example,lower/smaller minimum communication range minimum communication rangetransmissions may be favored (e.g., be given a higher priority) overlarger minimum communication range transmissions when congestion occurs(e.g., when a minimum communication range may not be met for largerminimum communication range transmissions due to congestion control). AWTRU may perform one or more of the following during congestion control.

The WTRU may set a default value for a TX related parameter (e.g., setTX power to 0). The WTRU may drop a transmission. The WTRU may stopperforming resource selection for a transmission. The WTRU may disableHARQ for a transmission. The WTRU may disable carrier aggregation for atransmission. The WTRU may suspend a SLRB and/or a LCH associated with atransmission.

A WTRU may be configured with a set of congestion-controlled TXparameters (e.g., such as a maximum TX power, a limit on the number ofretransmissions, a maximum number of selected subchannels, etc.). Theseparameters may be configured based on congestion, priority, and/ortransmission range. For example, the WTRU may be configured withrespective sets of congestion controlled parameters for differentcombinations of one or more of the following values, and the WTRU mayapply a set of congestion-controlled TX parameters that corresponds tothe combination of values associated with a measured CBR and a set oftransmission parameters being used. The one or more values may include,for example, a range of measured CBRs, a priority value (e.g., PPPP orLCH priority), a latency value, a reliability value, and/or a minimumcommunication range value or set of minimum communication range values.

A WTRU may determine or may be configured with a threshold minimumcommunication range. The WTRU may perform congestion control for atransmission differently based on whether the transmission has anassociated minimum communication range that is above or below theconfigured threshold minimum communication range. The WTRU may performcongestion control for a transmission differently based on whether ameasured CBR meets certain criteria (e.g., whether the CBR is above athreshold, for example, for transmissions of a specific priority). Forexample, when a measured CBR meets certain criteria (e.g., a set ofpreconfigured criteria), the WTRU may apply the default value of one ormore TX parameters (e.g., set maximum TX power to 0) for transmissionshaving a minimum communication range above a threshold. The WTRU maydetermine a single threshold or the WTRU may determine respectivethresholds for multiple destination L2 IDs (e.g., for each destinationL2 ID). The WTRU may determine the threshold(s) based on one or more ofthe following.

The WTRU may determine the threshold(s) based on a networkconfiguration. For example, the WTRU may be configured with one or morethreshold minimum communication ranges. Different threshold minimumcommunication ranges may be configured for different measured CBRlevels, for different LCH or PPPP priority levels, for different PQIvalues, and/or for different latency requirements associated with thesame data transmission.

The WTRU may determine the threshold(s) based on distance information(e.g., distance between the WTRU and other WTRU(s) or gNB(s)). Forexample, the WTRU may determine the threshold MCR based on explicitinformation about the distance between the WTRU and a peer WTRU. TheWTRU may calculate the threshold based on a peer WTRU that is theshortest distance away from the current WTRU. For example, the thresholdmay be calculated as a percentage of the shortest distance, where thepercentage may be configured (e.g., by a network).

The WTRU may determine the threshold(s) based on HARQ, CQI, and/or otherfeedback, for example, from a peer WTRU. For example, the WTRU maydetermine the threshold minimum communication range based on one or morefeedback received from a peer WTRU or multiple WTRUs. Such feedback mayinclude, for example, a measured power (e.g., RSRP) of the HARQ feedbackfrom one or more peer WTRUs, CQI reports from one or more peer WTRUs,ACK/NACK statuses from one or more peer WTRUs.

In examples, the WTRU may derive the threshold minimum communicationrange using (e.g., in accordance with) a preconfigured formula orfunction of the RSRP associated with a PSFCH transmission. The PSFCHtransmission may be received from a group of one or more WTRUs that areassociated with a same L2 destination ID (e.g., via a group or unicastlink) for which congestion control is being considered. The RSRP may bea minimum RSRP, a maximum RSRP, or an average RSRP, e.g., in the case ofgroupcast. The RSRP may correspond to the last PSFCH transmission from agroup of one or more WTRUs associated with a group or unicast link. TheWTRU may compute an average RSRP of such PSFCH transmissions over aperiod of time (e.g., over a time window). The WTRU may use the averageRSRP to compute the threshold minimum communication range.

A WTRU may treat transmissions without a configured minimumcommunication range requirement (e.g., for unicast or groupcasttransmissions) as having a maximum minimum communication range or aninfinite minimum communication range. Such transmissions may be subjectto legacy congestion control (e.g., without consideration of minimumcommunication ranges). For example, these transmissions may not bedropped or de-prioritized when a range cannot be met.

A SLRB may be specifically configured to meet certain QoS requirements.

SLRB configurations mapped to a QoS profile may be limited (e.g., for aWTRU in IDLE mode) due to SIB overheads and/or non-standardized PQIsthat require the broadcasting of QoS information (e.g., all QoSinformation).

A WTRU may be configured to select an SLRB configuration (e.g., amongmultiple configurations) that best represents the QoS profile of a flow.

A WTRU may determine the SLRB configuration for a specific QoS profileand/or flow that is not configured by the network (e.g., via SIB,preconfiguration, or dedicated signaling) by selecting a configured SLRBconfiguration that best represents the QoS profile or flow. The WTRU maymake such a determination based on the similarity of QoS parametervalues in the QoS profile (e.g., the QoS profile associated with aconfigured flow).

A WTRU may be configured with one or more QoS profiles (e.g., equivalentQoS profiles) for a QoS flow (e.g., in addition to an actual QoSprofile). Such configuration may be provided from an upper layer, forexample. A WTRU configured with a flow associated with anon-standardized PQI may be configured with one or more standardizedPQIs (e.g., equivalent standardized PQIs), and may select theconfiguration associated with such standardized PQI when establishing aSLRB for the non-standardized PQI flow.

A WTRU may determine which of the configured SLRB configurations to usefor a QoS flow or profile that does not have a network configuration,for example, by selecting the SLRB configuration associated with a QoSprofile that has one or more similar QoS parameters which are the sameor similar. For example, the WTRU may select the SLRB configurationassociated with a QoS profile that has the same latency requirement(e.g., in the PQI), the WTRU may select the SLRB configurationassociated with a QoS profile that has the same reliability requirement(e.g., in the PQI), etc.

Although the examples described herein may consider LTE, LTE-A, NewRadio (NR) or 5G specific protocols, it is understood that the examplesdescribed herein are not restricted to those scenarios and may beapplicable to other wireless systems as well.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

1. A wireless transmit receive unit (WTRU), comprising: a processorconfigured to: determine that a set of resources is available for theWTRU to perform a sidelink transmission; determine one or more logicalchannels in response to determining that the set of resources isavailable, wherein each of the one or more logical channels isassociated with a respective bucket size parameter and a respectivepriority, and wherein the one or more logical channels are determinedbased on a determination that each of the one or more logical channelshas data for transmission and that the respective bucket size parameterassociated with each of the one or more logical channels has a valuegreater than zero; select a first destination for the sidelinktransmission, wherein the first destination is associated with a firstlogical channel of the one or more determined logical channels andwherein the first logical channel has a highest priority among the oneor more determined logical channels; and transmit data associated withthe first logical channel to the first destination using at least aportion of the set of resources available for the sidelink transmission.2. The WTRU of claim 1, wherein the respective bucket size parameterassociated with each of the one or more determined logical channels isdetermined based on at least a prioritized bit rate.
 3. The WTRU ofclaim 1, wherein the respective bucket size parameter associated witheach of the one or more determined logical channels is determined basedon at least a bucket size duration.
 4. The WTRU of claim 1, wherein theset of resources available for the sidelink transmission is scheduled bya network.
 5. The WTRU of claim 1, wherein the set of resourcesavailable for the sidelink transmission is selected by the WTRUautonomously.
 6. The WTRU of claim 5, wherein the set of resourcesavailable for the sidelink transmission is selected by the WTRU from apreconfigured pool of resources.
 7. The WTRU of claim 1, wherein theprocessor is further configured to determine a second logical channelassociated with the first destination from the one or more determinedlogical channels based on respective minimum communication ranges (MCRs)of the first logical channel and the second logical channel, theprocessor further configured to multiplex the second logical channelwith the first logical channel.
 8. The WTRU of claim 7, wherein theprocessor is configured to determine the second logical channel based ona determination that a difference between the respective MCRs of thefirst logical channel and the second logical channel is less than athreshold.
 9. The WTRU of claim 1, wherein the processor beingconfigured to transmit the data associated with the first logicalchannel to the first destination comprises the processor beingconfigured to determine an amount of data to be transmitted to the firstdestination based on the bucket size parameter associated with the firstlogical channel.
 10. The WTRU of claim 1, wherein the processor isfurther configured to: determine that the bucket size parameterassociated with a second logical channel of the one or more determinedlogical channels has a value greater than zero, that the priorityassociated with the second logical channel is equal to the priorityassociated with the first logical channel, and that the second logicalchannel is associated with a second destination; and select the firstdestination over the second destination on a condition that selectingthe first destination results in fewer resources being utilized totransmit data that exceeds a bucket size requirement than selecting thesecond destination.
 11. A method implemented by a wireless transmitreceive unit (WTRU), the method comprising: determining that a set ofresources is available for the WTRU to perform a sidelink transmission;determining one or more logical channels in response to determining thatthe set of resources is available, wherein each of the one or morelogical channels is associated with a respective bucket size parameterand a respective priority, and wherein the one or more logical channelsare determined based on a determination that each of the one or morelogical channels has data for transmission and that the respectivebucket size parameter associated with each of the one or more logicalchannels has a value greater than zero; selecting a first destinationfor the sidelink transmission, wherein the first destination isassociated with a first logical channel of the one or more determinedlogical channels and wherein the first logical channel has a highestpriority among the one or more determined logical channels; andtransmitting data associated with the first logical channel to the firstdestination using at least a portion of the set of resources availablefor the sidelink transmission.
 12. The method of claim 11, wherein therespective bucket size parameter associated with each of the one or moredetermined logical channels is determined based on at least aprioritized bit rate.
 13. The method of claim 11, wherein the respectivebucket size parameter associated with each of the one or more determinedlogical channels is determined based on at least a bucket size duration.14. The method of claim 11, wherein the set of resources available forthe sidelink transmission is scheduled by a network.
 15. The method ofclaim 11, wherein the set of resources available for the sidelinktransmission is selected by the WTRU autonomously.
 16. The method ofclaim 15, wherein the set of resources available for the sidelinktransmission is selected by the WTRU from a preconfigured pool ofresources.
 17. The method of claim 11, further comprising determining asecond logical channel associated with the first destination from theone or more determined logical channels based on respective minimumcommunication ranges (MCRs) of the first logical channel and the secondlogical channel, and multiplexing the second logical channel with thefirst logical channel.
 18. The method of claim 17, wherein the secondlogical channel is determined based on a determination that a differencebetween the respective MCRs of the first logical channel and the secondlogical channel is less than a threshold.
 19. The method of claim 11,further comprising: determining that the bucket size parameterassociated with a second logical channel of the one or more determinedlogical channels has a value greater than zero, that the priorityassociated with the second logical channel is equal to the priorityassociated with the first logical channel, and that the second logicalchannel is associated with a second destination; and selecting the firstdestination over the second destination on a condition that selectingthe first destination results in fewer resources being utilized totransmit data that exceeds a bucket size requirement than selecting thesecond destination.
 20. The method of claim 11, wherein transmitting thedata associated with the first logical channel to the first destinationcomprises determining an amount of data to be transmitted to the firstdestination based on the bucket size parameter associated with the firstlogical channel.